Note: Descriptions are shown in the official language in which they were submitted.
~3~7~3~
The present invention xelates to chemically joined,
phase separated thermoplastic graft copolymers.
More particularly this invention relates to a novel
composition of matter comprising: high molecular weight poly-
merizable monomers, each of said polymerizable monomers com-
prising at least one polymeric segment having at least about
20-30 uninterrupted recurring monomeric units of an anionical-
ly polymerized vinyl-containing compound, each of said poly-
merizable monomers terminating with no more than one polymer-
izable end group containing a moiety selected from olefinic,epoxy or thioepoxy groups per mole of said polymerizable mono-
mers, said polymerizable monomers denoted as having a substan-
tially uniform molecular weight distribution such that their
ratio of Mw/~n is less khan about 1.1, wherein ~w is the weight -
average molecular weight of the high molecular weight polymer-
-
izable monomers and Mn is the number average molecular weight
of the high molecular weight polymerizable monomers, said poly-
merizable monomers being further denoted as capable of copoly-
merizing with a second polymerizable compound having a rela-
tively low molecular weight to yield a chemically joined,phase separated thermoplastic graft copolymer, said copolymer-
ization occurring through said polymerizable end group, said
polymerizable end group thereby occurring as an integral part
of the backbone of said chemically joined, phase separated
thermoplastic graft copolymer.
This invention also discloses a monofunctional
polymerizable macromolecular monomer composition represented
by the formula:
R - - Z ~ X
_ _~
wherein R is lower alkyl, Z is a repeating monomeric unit of a
~Q37~3!~i
vlnyl-containing compound, n is a positive integer having a
value of at least about 209 and X is a polymerizable end group
containing a moiety selected from olefinic~ epozy or thioepoxy
groups~ said polymerizable macromolecular monomer being denoted
as having a substantially uniform molecular weight distribution
such that its ratio of Mw/Mn is less than about lo 13 wherein
MW is the weight average molecular weight of the macromolecu-
lar monomer and Mn is the number average molecular weight of
the macromolecular monomer.
Further there is disclosed herein a process for pro-
ducing high molecular weight polymerizable monomers~ said pro-
cess comprising the st~ps ofO (a) polymerizing an anionically
- polymerizable vinyl~containing monomer in the presence of an
anionic .I.nitiator to produce a monofunctional living polymer
denoted as having a substantially uniform molecular weight
distribution such that its ratio of Mw/Mn is less than about
lol~ wherein Mw is the weight average molecular weight of the
monofunctional living polymer and Mn is the number average
molecular weight of the monofunctional living polymer~ (b) re-
acting said monofunctional living polymer with either a halo-
gen-containing compound which also contains either a polymer-
izable olefinic group or an epoxy or thioepoxy group or a com-
pound whlch contains a reactive ~ite to the anion of the liv-
ing polymer whlch also conta.ins a polymerizable moiety which
does not preferentially react with said anion3 said polymer-
izable moiety being comprised of an olefinic group9 said re-
action with said monofunctional living polymer being conducted
at substanti.ally the same temperature at which the living
polymer was prepared~ said compound being reacted with sa~d
monofunctional living polymer on a mole-for mole basis with
respect to the amount of anionic initiator used to prepared
--2~
~7~3$
said monofunctional living polymer, and ~c) recovering said high molecular
weight polymerizable monomers, each of said polymerizable monomers comprising
at least one polymeric segment having at least about 20 uninterrupted
recurring monomeric units of an anionically polymerized monomer, each of
said polymerizable monomers terminating with no more than one polymerizable
end group per mole of said polymerizable monomers, said polymerizable
monomers denoted as having a substantially uniform molecular weigh~ distri- ;
bution, such that their ratio of Mw/Mn is less than about l.l, said poly-
merizable monomers being further denoted as capable of copolymerizing with a
second polymerizable compound having a relatively low molecular weight to
produce a chemically joined, phase separated thermoplastic graft copolymer,
said copolymerization occurring through said polymerizable end group, said
polymerizable end group thereby occurring as an integral part of the back-
bone of said chemically joined, phase separated thermoplastic graft co-
polymer,
The present inv.ontion provides a chemically joined, phase separated
thermoplastic graft copolymer of a copolymerizable macromolecular monomer
represented by the formula
I - ~Pl)n (X) - (Y)
and at least one copolymerizable backbone-forming comonomer; wherein I is
the residue of a monofunctional anionic initiator, Pl is at least one
anionically polymerized monomer, X is a capping agent, Y is a terminating
agent having a copolymerizable end group, n is at least about 20, w is zero
or l, and wherein said copolymerizable end group and said backbone-forming
comonomer form the backbone of the graft copolymer and the macromolecular
monomers form the sidechains of the graft copolymer, characterized in that
a. said copolymerizable macromolecular monomers comprise from about 1%
to about 95% by weight of the graft copolymer and said backbone-forming
comonomers comprise from about 99% to about 5% by weight of the graft co-
polymer, said copolymerizable macromolecular monomers having a substantially
~s ~,
, ~ - 3 -
~L~37!~3!~
uniform molecular weight distribution such that the ratio of Mw/Mn is less
than about 1 1, wherein Mw is the weight average molecular weight of the
macromolecular monomers and Mn is the number average molecular weight of
the macromolecular monomers, and b. the polymeric sidechains of the graft
copolymer which are copolymerized into the backbone are separated by at
least about 20 uninterrupted recurring polymerized units of the backbone-
forming comonomer, the copolymerizable end group o:E the macromolecular
monomers and the backbone-forming comonomer having been chosen with regard
to their reactivity ratios so as to control the distribution and copoly-
merization of the macromolecular monomers along the backbone, and c. said
graft copolymer contains a member selected from the group consisting of:
~i) at least one backbone-forming comonomer selected from the group con-
sisting of acrylic acid, methacrylic acid, acrylamide, N-alkylacrylamide,
N,N-dialkylacrylamide, methacrylamide, N-alkylmethacrylamide, N,N-dialkyl-
methacrylamide, acrylonitrile, methacrylonitrile, vinyl chloride, vinyl-
idene cyanide, vinyl acetate, vinyl propionate, vinyl chloroacetate, fumaric
acid and its esters, and maleic anhydridesJ acids and esters; and at least
one graft monomer containing members selected from the following groups
(ii) a residue of an alkali metal salt of a tertiary alcohol as the anionic
polymerization initiator, I; ~iii) a capping agent, X, selected from 2-
butenylene or 2-methyl-2-butenylene radicals; (iv) a terminating`agent, Y,
selected from
fH2
CH2 = C - CH = CH2,
~0
- R C - C
Il \
Il /
HC C
~0
~37~ii36
~0
OR
OR,
- C
~0
R3 ~ _ CH = C~l2,
R3- O-CH2 ~ CH = CH2,
o
- R3- O C - CH
HO C - CH
O
; OH O
- R CH - CH2 - O - Ci - CR =`CH2, and
OH O
-R3- CH - CH2 - O C - CH ; and
11
HO - C - CH
o
wherein R3 is an alkylene radical, and R is a hydrogen or an alkyl group;
(v) a macromolecular monomer polymeric portion ~Pl)n, comprising a polymeric
segment of a vinyl aromatic hydrocarbon having a molecular weight in the
range of from about 5,000 to 50,000 and a polymeric segment of a conjugated
diene containing 4 to 12 carbon atoms per molecule.
The present invention also provides a process for preparing a
graft copolymer comprising polymerizing at least one anionically poly-
merizable monomer in the presence of an anionic polymerization initiator
to thereby form a monofunctional living polymer; and where required reacting
the monofunctional living polymer with a capping agent; reacting the .
~ _ 5 _
7~3~
monofunctional living polymer with a terminating agent to thereby form
copolymerizable macromolecular monomers with a copolymerizable end group,
and thereafter, copolymerizing by free radical, cationic, anionic, con-
densation, Ziegler or Natta processes from about 1 to 95% by weight based
on the weight of the resulting graft copolym~r oflsaid copolymerizable end
group with from about 99 to 5% by weight of the resulting graft copolymer
of a backbone-forming comonomer; wherein said copolymerizable end group
and said backbone-forming comonomer form the backbone of the graft co-
polymer and the macromolecular monomers form the side-chains of the graft
copolymer, characterized in that ~a) said copolymerizable macromolecular
monomers comprise from about 1% to about 95% by weight of the graft co-
polymer and said backbone-forming comonomers comprise from about 99% to
about 5% by weight of the graft copolymer said copolymerizable macromole-
cular monomers having a substantially uniorm molecular weight distribution
such that the ratio of ~w/~n is less than about 1.1, wherein ~w is the
weight average molecular weight of the macromolecular monomers and Mn is
the number average molecular weigh~ of the macromolecular monomers, and
(b) the polymeric sidechains of the graft copolymer which are copolymerized
into the backbone are separated by at least about 20 uninterrupted recurring
polymerized units of the backbone-forming comonomer, the copolymerizable
end group of the macromolecular monomers and the backbone-forming monomer
having been chosen with regard to their reactivity ratios so as to control
the distribution and copolymerization of the macromolecular monomers along
the backbone, and ~c) said graft copolymer contains a member selected from
the group consisting of: (i) at least one backbone-forming comonomer
selected from the group consisting of acrylic acid, methacrylic acid;
acrylamide; N-alkylacrylamide; N,N-dialkylacrylamide; methacrylamide;
N-alkylmethacrylamide; N,N-dialkylmethacrylamide; acrylonitrile; meth-
acrylonitrile, vinyl chloride; vinylidene cyanide; vinyl acetate; vinyl
propionate; vinyl chloroacetate; fumaric acid and its esters;and maleic
anhydrides, acids and esters; and at least one graft monomer containing a
~ r~
~ - 5a -
76i3~
member selected from the following groups (ii) a residue of an alkali metal
salt of a tertiary alcohol anionic polymerization initiator; (iii) a capping
agent selected from butadiene or isoprene; (iv) a copolymerizable end group
derived from a terminating agent selected from 2-halome~hyl-1,3-butadiene,
haloalkylmaleic anhydride, haloalkylmaleate esters, vinyl haloaryls, vinyl
haloalkaryls, maleic anhydride, acrylic anhydride, methacrylic anhydride,
and a epihalohydrin, the epoxy group of which is hydrolyzed and then reacted
with acrylyl halide, methacrylyl halide or maleic acid halide; ~v) a macro-
molecular monomer having a polymeric segment of a vinyl aromatic hydrocarbon
with a molecular weight in the range of from about 5,000 to 50,000 and a
polymeric segment of a conjugated diene containing 4 to 12 atoms per molecule;
and combinations thereof.
In accordance with the present invention there is also provided
a polyblend comprising: (1) from about 1 to about 50 parts by weight of
the chemically joined, phase separated thermoplastic graft copolymer from
99 to about 50 parts by weight of a polymer selected from polyethylene, poly-
propylene, polybutadiene, polyisoprene, polystyrene, poly~vinyl chloride),
polyacrylonitrile, polyacrylamides and mixtures thereof.
Polymer technology has developed to a high degree of sophisti-
cation and extensive research efforts in this direction are being undertaken
to obtain improvements in polymer properties. Some of these efforts lead
to polymer materials capable of competing with metals and ceramics in
engineering applications. Generally, it is a requirement that these polymers
be crystalline, since crystalline polymers are strong, tough, stiff and
generally more resistant to solvents and chemicals than their non-crystalline
counterparts.
Many poly alpha-olefins are crystalline and have excellent
structural integrity; and, accordingly, have acquired increasing commercial
acceptance as materials for competing with metals and ceramics. As one
example, polyethylene has been regarded as one of the most important
~ / ~ - 5b -
~37~i3~ :
polymers among the major plastics, with its production reaching about 6
billion pounds in 1970 (1.7 billion pounds of high density linear poly-
ethylene and 4.3 billion pounds of low density polyethylene).
Despite the widespread use of this important plastic, its use
has been limited to flexible, translucent, molded articles or flexible,
clear films, due to its softness. The uses of polyethylene have also been
limited due to its poor adhesion of many substrates and its low heat distor-
tion, rendering it unsuitable for many high temperature applications.
- 5c -
~3t7~,3~,
Attempts by prior art workers to co~bine the proper_
ties of polyole~ins and other polymers by either chemical or
mechanical means generally has resulted in a sacrifice o~ many
of the beneficial proper~ies of both the polyolefin and the
additional polymerO ~or example, graft copolymers of poly-
ethylene and polypropylene have been prepared only with di~
culty du~ to the inertness these polymers have with many other
polymerizable monomers and polymers. The resultant graft ¢o-
polymer generally has been a mixture which also contains free
homopolymers
Polyblends o~ a polyalefin with another polymer pre-
pared by blending quantities of the two polymers together bY
mechanical means have been generally unsuitable for many ap-
plications due to their adverse solubility or extractability
properties when used with various solvent systems, particular-
ly when containing a rubbery, amorphous component.
The above consideratio~s recognized by those skilled
in the art with respect to the incompatibility of polyolefins
with other polymers ~ind almost equal applicabili~y ln the
case of other plastics such as the polyacrylates, polymeth-
acrylates, polyvinylchlorides, etc. Thus, the incompatability
o~ both natural and syn~hetic polymers becomes increasingly
apparent as more and more polymers having particularly good
properties for special uses have become available, and as efT
forts have been made to combine pairs of these polymers ~or
the purpose of incorporating the di~erent~ good properties o~
each polymer into one product, More often than not, these e~-
forts have been unsuccessful because the resulting blends have
exhibited an instability, and in many cases the desirable
properties o~ the new polymers were completely lost, As a
specific example, polyethylene is incompatible with poly-
--6--
~3763~
styrene and a blend of the t~o has poorer physical propert~es
than either o~ the ~omopolymers. These failures were at first
attributed to inadequate mixing proceduresg but aventually ~t
was concluded that the ~ailures were due simply to the inher-
ent incompatibilitiesO Although it i8 now believed that this
is a correct explanation, the general nature o~ such incompat-
~bility has remained somewhat unclear, even to the presentO
Polarity seems to be a factor, i.e., two polar polymers are
apt to be more compatible than a polar polymer and a non-polar
polymer. Also9 the two polymers must be structurally and com-
positionally somewhat similar if they are to be compatible.
Still ~urther, a particular pair of polymers may be compatible
only within a certain range o~ relat:Lve proportions of the two
polymers; outside that range they are incompatible.
Despite the general acceptance of the fact of incom-
patibility of polymer pairs, there is much interest in devis-
ing means whereby the advantageous properties of combinations
of polymers may be combined into one product.
One way in which this ob~ective has been sought in-
volves the preparation of block or gra~t copolymers. In thisway, two different polymeric segments, normally incompa~ible
with one another, are ~oined together chemically to give a
sort of forced compatibility. In such a copolymer, each poly-
mer se~ment continues to manifest its independent polymer
propertiesO Thusg the block or graph copolymer in many in-
stances possesses a combination o~ properties not normally
found in a homopolymer or a random copolymer.
Recently9 there has been described a method Por pre-
paring gra~t copolymers of controlled branch configuration~
It is described that the gra~t copolymers are prepared by
first preparing a prepolymer by reacting a vinyl metal com-
-7~
`:`'
~Q37~:i3~
pound with an ole~inic monomer to obtain a vinyl terminated
prepolymer. A~ter protonation and catalyst removalg the pre-
pol~mer is dissolved in an inert solvent with a polymerization
catalyst and is thereafter reacted with ei:ther a di~erent
polymer having a reactive vinyl group or ~ different vi~yl
monomer under free-radical conditions.
The current limitations on the preparation of these
copolymers are mechanisticO Thus, there is no means ~or con-
trolling the spacing of the sidechains along the backbone
chain and the possibility of the sidechains having irregular
sizes. Due to the mechanistic li~itations of the prior art
methods, i.e.g the use of an alPha-olefin terminated prepoly-
mer with acrylonitrile or an acrylate monomer, complicated
mixtures o~ free homopolymers result.
In ~iew of the above considerations, it would be
highly desirable to devise a means for preparing graft copoly-
mers wherein the production of complicated mixtures of free
homopolymers is minimized and the beneficial properties of the
sidechain and backbone polymer are combined in one product.
Moreoverg it is recognized and documented in the
literature that vinyl lithium is one of the slowest anionic
polymerization initlators. The slow initiator characteristic
of vinyl lithium when used to polymerize styrene pr~duces a
polymer having a broad molecular weight distribution due to
the ratio of the overall rate of propagation of the styryl
anion to that of the vinyl lithium initiation. In other wordsJ
the molecular weight distribution of the polymer produced will
be determined by the effective reactivity of the initiator
compared with that of the propagating anionic polymer species3
i.e., vinyl lithium initiator reactivity compared to the styryl
anion. Accordingly~ following the practice of UOSo Patent No.
--8--
~ ~ ~ -
7~3~
3,235,626, a gra~t copolymer having sidechains of uniform mo-
lecular weight cannot be preparedO
The prior art also describes processes for term.in-
ating free-radical and ionic polymerized polymers with func-
tional groups which are described as capable of copolymerizing
with polymerizable monomersO The ~unctionally terminated pre-
polymers descri.bed by these patentees also would be expected
to have a broad molecular weight distribution and, therefore,
would not be capable of producing a chem~cally ~oined, phase
separated thermoplastic gra~t copolymer
The present invention relates to thermoplastic graft
copolymers comprised o~ copolymeric backbones containing a
plurality of uninterrupted repeating units of the backbone
polymer and at least one integrally copolymerized moiety pçr
backbone polymer chain having chemica~ly bonded thereto a sub-
stantially linear polymer which forms a copolymerized side-
chain to the backbone, wherein each of the polymeric side-
chains has substantially the same molecular weight and each
polymeric sidechain is chemically bonded to only one backbone
polymer.
The gra~t copolymers o~ the present invention assume
a "T~ type structure when only one sidechain is copoly~erized
into the copolymeric backbone, However, when more than one
sidechain is copolymerized into the backbone polymer, the
graft copolymer may be characterized as having a comb-type
structure illustrated in the following manner:
c-c-c-b.-c-c-c-b-c-c-c b-c-c-c
a a a
.
a a a
.
a a a
wherein "a" represents a substantially linear, uniform molecu-
_g _
.
7~3~
lar weight polymer or copolymer having a suf~icient molecular
weight such that the physical prqperties of at least one o~
the substantially linear polymers are manifest; "b" repre~ents
a reacted and polymerized end group chemically bonded to the
sidechain, t'a", which is integrally polyme-rized into the back-
bone polymer3 and "c" is the backbone polymer having uninter-
rupted segments of sufficient molecular weight such that the
physical properties o~ the polymer are manifest
The backbone of the graft copolymers o~ the present
invention pre~erably contains at least about 20 unlnterrupted
recurring monomeric units in each segment. It has been found
that this conditlon provides the graft copolymer the properties
of the polymer. In other words, thq presence o~ segments con-
talning at least about 20 unlnterrupted recurring monomeric
units provides the graft copolymers with the physical proper-
ties attributed to this polymer, such as crystalline melting
point (Tm) and structural integrit~.
The backbone polymeric segments of the chemically
joined, phase separated thermoplastic gra~t copolymers o~ the
present invention are derived from copolymerizable monomers,
preferably the low molecular weight monomersO These copol~-
merizable monomers include polycarboxylic acids, their anhy-
drides and amides, polyisocyanates, organic epoxides, includ-
ing the thioepoxides, urea-formaldehydes, siloxanes, and
ethylenically unsaturated monomers. A particularly preferred
group of copo ymerizable monomers includes the ethylenically-
unsaturated monomers, especially the monomeric vinylidene type
compounds, i.e,, monomers containing at least one v~nylidene
t
CH2 = C- group. The vinyl type co~pounds represented by the
--10 -
~3~36
H
formula CH2 = C - wherein a hydrogen is attached to one of
the ~ree valences o~ the vinylidene group are cont~mplated as
falling within the generic scope of the vinylidene compounds
re~erred to hereinabove.
The backbone polymers o~ the pre~sent invention are
also comprised oP polyolefins which includes polymers of alpha-
ole~ins of the formula-
C~2 = CHR
wherein R is either hydrogen, or an alkyl or aryl radical con-
taining 1 to about 16 carbon atoms, and include ethyl~ne., pro-
pylene, butene-l, pentene~l, hexene-lg styrene, etcO, copoly-
mers o~ alpha-ole~ins including the ethylene-propylene copoly-
mers; and polymers o~ poly~erizable dienes including butadiene,
isoprene, etcO
The copolymerizable monomers useful in the practice
o~ the present invention are not limited by the exemplary
classes o~ compounds,mentioned above. The only limitation on
the particular monomers to be employed is their capability to
copolymerize with the polymerizable end groups of the sidechain
prepolymer under free-radical, ionic, condensation, or coordin~
ation ~Ziegler or Ziegler-Natta catalysis) ~o~ymerization re-
actions. AB it will be seen ~rom the description o~ macromo-
lecular monomers, described hereinbelow, the choice of poly-
merizable end groups includes any polymerizable compound com-
mercially avail~ble. Accordingly, the choice o~ respective
polymerizable end group and copolymerizable monomer can be
chosen, based upon relative reactivity ratios under the respec-
tive copolymerization reaction conditionR suitable ~or copoly-
merization reaction, For example, alPha-olefins copolymerize
with one another using Ziegler catalysts, and acrylates co-
-11--
:
~3'~i3i
polymerize with vinyl chloride, acrylonitrile and other alkyl
acrylates. Accordingly, an ~ olefin terminated macromolec-
ular monomer copolymerizes with ethylene and ~ olefins us-
ing a Ziegler catalyst and an acrylate or methacrylate termin-
ated macromolecular monomer copolymerizes with vinyl chlorideg
acrylonitrile, acrylates and methacrylates under ~ree radical
conditions in a manner governed ~y the r~spective reactivity
ratios for the comonomersO
As will be explained hereinafterg the excellent com-
bination o~ beneficial properties possessed by the gra~t co~polymers o~ the present invention are attributed to the large
segments of uninterrupted copolymeric backbones and the in-
tegrally copolymerized llnear sidechains o~ controlled molecu-
lar weight and narrow molecular weight distribution.
The term "linear", referred to hereinaboveJ is being
used in its conventional sense, to pertain to a polymeric back-
bone that is ~ree ~rom cross-linking.
The sidechain polymers having substantially uni~orm
molecular weight are comprised o~ substantiallg linear poly-
mers and copolymers produced by anionic polymerization o~ anyanionically polymerizable monomer~ as will be described herein-
after. Preferably, the sidechain polymer wlll be di~ferent
than the backbone polymerO
It is pre~erred that at least one segment of the
sidechain polymer of the graft copolymers of the present in-
vention have a molecular weight su~icient to manifest the
bene~icial propertles of the respective polymerO In other
words, physical properties o~ the sidechain polymer such as
the glass transition temperature (Tg) will be mani~estO Gen-
3Q erally, as known in the art, the average molecular weight o~the segment of the polymeric sidechains necessary to estab-
-12-
~37~3 Ei
lish the physical properties of the polymer will be ~rom about5,000 to about 50,0000
In light of the unusual and improved physical proper-
ties possessed by the thermoplastic graft copolym~rs of the
present inventiong it is believed that the mono~unctionally
bonded polymeric sidechains having substantially uniform mo-
lecular weight form what is known as "glassy domains" repre-
senting areas of mutual solubilit~ of the respect~ve sidechain
polymers from separate backbone copolymersO
Figure I illustrates the normalized stress~strain
properties versus percent polystyrene macromolecular monomer
incorporation in polyethyleneO
Figure II illustrates the normalized ~lexural modu-
lus and heat deflection versus percent polystyrene macromolec-
ular monomer incorporation in polyethylene.
Briefly, the chemi~ally joined, phase se~arated
thermoplastic gra~t copolymers of the present invention are
prepared by first preparing the sidechains in the ~orm of
mono~unctional living polymers o~ substantially uniform molecu-
lar weight. The living polymers are therea~ter terminated, asby reaction with a halogen-containing compound that also con-
tains a reactive polymerizable group, such as, for example, a
polymerizable olefinic or epoxy group, or a compound which
contains a reactive site to a carbanion of the llving polymer
and a polymerizable moiety which does not pre~erentially react
- with the carba~ion~ e.gO, maleic anhydrideO The monofunction-
al terminated living polymer chains are then polymerized,
together with the backbone monomer9 to form a chemically
joined, phase separated thermoplastic gra*t copolymer wherein
the polymeric sidechains are integrally polymerized into the
backbone polymer~
-13
~3'7~3~
The chemically joinedg phase separated thermoplastic
graft copolymers derived ~rom ethylenlc~lly unsaturated mono-
mers as the backbone comonomer generally correspond to the
~ollowing structural ~ormulau
H~---- C ~ H2- C ~ C~z
X' X X'
y
wherein R' and R" are each selected from the group consisting
o~ hydrogçn, lower alkylJ cycloalkyl, and aryl ~adicals; X and
X' are each selected ~rom the group consisting~of hydrogen,
_ _ ,
alkylene radicals (i.e., - CH2 _ - , x is a positive integer
whereln the terminal methylene group in X' i~ either hydrogen,
lower alkyl, e.g., methyl, halogen, etct, and in the case o~
X, joins the backbone polymer with the sidechain polymer) a
O O
" ..
saturated ester (i.e., - C--OR or -O- C -Rj wherein R is
alkyl or aryl), nitrile (i.e., C-N), amide (i.eO,
0 / Rl
- C--N wherein R~ and R" are either hydrogen, alkyl or
\ R"
~ R'
aryl radicals)J amine (i.e.3 - N wherein R' and R'9 are
R"
either hydrogen, ~lkyl or aryl radicals), isocyanate, halogen
ti,e., F, Cl, Br or I) and ether (i.e.j O---R, wherein R is
either alkyl or aryl radicals)~ X and X' may be the same~or
di~erent, However, in the case where X9 iS, an ester, X should
be a functional group such as ester9 halogen, nitrile, etc.,
as explained hereinabove with respect to the respective re-
wl4 ~ ~
~7~i3$
activity ratios o~ the comonomers used to prepare the gra~tcopolymers; Y is a substantially linear polymer or copolymer
wherein at least one segment of the polymer has a suf~icient
molecular weight to mani~est the properties of the respective
polymer, iOe., a molecular weight of ~rom about 5,000 to about
150,000, very suitable polymers having a molecular weight in
the range of from about 5,000 tq about 50,000, pre~erably a
molecular weight o~ from about 10,000 to about 35,000~ more
preferably 12JOOO to about 25,000; the symbols ~, b and c are
positive integersj wi~h the proviso that a and b are each a
value such that the physical properties o~ the uninterrupted
segments in the backbone, e.gO, Tm, are mani~st, preferably
at least about 20; and the symbol c is at least one, but pre~-
erably greater than one, eOg., a value such that the molecular
weight of the graft copolymer will be up to about 2,000,0~0.
The formation of the graft copoly~ers o~ the present
invention may be better understood by reference to the ~ollow-
lng reactions illustrated by the equations set ~orth below
wherein the invention is illustrated in terms of polystyrene
sldechains and polyethylene backbones. It can be seen ~rom
these equations that the first reactions involve the prepara-
tion of living polymers of polystyrene. The living polymers
are thereafter reacted with a molar equivalent o~ allyl chlo-
ride, wherein the reaction takes place at the carbon-chloride
bond) rather than at the carbon-carbon double bond~ The vinyl
terminated polystyrene, referred to herrein as the alPha-ole~in
terminated macromolecular monomer, is then copolymerized with
ethylene to produce a graft copolymer of polyethylene, whereby
the vinyl moiety o~ the polystyrene is integrally polymerized
into the linear polyethylene backbone.
Alternatively, the living polymer can be reacted
-15
~7~3~
with an epoxide such asJ for example) ethylene oxide, to pro-
duce an alkoxide ion which can then ~e reacted wi~h the halo~
gen-containing olefin~ i.eO, allyl chloride, to produce an
alpha-ole~in termlnated m~cromolecular monomerO This, in es-
sence) places the terminal alpha-ole~in ~arther away from the
aromatic ring of the ~olystyrene and there~ore reduces any
steric hindering influence that migh~ be exerted by the aro-
matic ring.
~3763~
with an epoxide such as, for example, ethylene oxide, to pro-
duce an alkoxide ion which can then be react~d wi~h the halo
gen-containing ole~in, io e., allyl chloride, to produce an
alpha-olefin term~nated macromolecula~ monomer. This, in es-
sence, places the terminal alpha-ole~in ~arther away ~rom the
aromatic ring o~ the polyst~rene and there~ore reduces any
steric hindering in~luence that migh~ be exerted by the aro-
matic ring.
.
~037636
FORMATION OF THE GRAFT COPO~YMER 0~ ALPHA-OLEFIN
.. ., . . . . . . , , . . .. . " .,
~ TERMINATED POLYSTYRENE SIDECHAIN AND POLYETHYLENE BACKBVNE
, -- , .. . . . . .
: CH3C~I2(CH3)CHLi + CH2 = CH
CH CH (CH )C~ ~3 6?
',, 0
Propagation: (n-l)CH2 = CH
¢~
3 2(C 3)CH l GH ~ ~ CH ~ + Li~9
~0 Termdnation ~ith
Active End Group. CH2 ~ CHCH Cl
~ 2
CH3CH2(CH3)CH ~ CH ~ ~ CH2CH ~ CH2 + LiCl
Gra,~t Co~o,l.vmeriz,ation: xCH2 = CH2 ~ Polymerization Catalyst
2- ~ ( 2 CH ~ H2 CH ~ ,~
] ~ I
~0 In the equations above, the symbols a, b, ç, n.and X
are positive inte~ers wherein a and b are at least abo~t 20~ n
has a value of from about 50 to about 500, and x has a ~lue
-17-
-- \
`` ` ~037636
FORMATION OF THE GRAFT COPOLYMER OF ALPHA~OIEFIN
TERMI~ATED POIi~STYRENE SIDECHAIN AND POLYl~T~IYLENE BACKBON:E
.... .....
Initlatlon: CH3CN2(CH3)CHLl + CH2 = CE
CH~CH2 ( CH3 ) CHCH2~H -~ Li~)
~, ~
Pro~a~atlon: ¦ (n-l)CH2 = C
3 2( 3) H--CH2CH--- CH ~)H
L ~ ~n~
10 Termina~lon ~i~h
Active End Group:CH2 =~ CHCH2Cl
CH3CH2(CH3)CH~CH[~ CH2CH - CH2 + LiCl
Gra~t coDol.~merization: XCH2 - CH2 ~ polyrnerizatiQn`~ca~alyst
r ~CH2--CH2 ~ ( 'H- , . -CH ~ EH2 C
~13CH2(CH3)C ~ CH2- CH ~ ¦ ~
~Q In the equatlons ab~ve, the symbols a, b, c, n.and X
are positive integers wherein a and b are a~ least about 20~ n
has a value of ~rom about 50 to about ~00, and x has a v~lue
~03763~;
correspondi.ng approximately to the sum o~ a and b.
The sidechains o~ the chemically joinedg phase sepa-
rated graft copolymers, above, are preferably prepared by the
anionic polymerization of a polymerizable monomer or combina-
tion of monomersO In most instancesg such monomers are those
having an ole~inic group, such as the vinyl containing com-
pOU~9 although the olefinic containing monomers may be used
1. in combination with epoxy or thioepoxy containing compounds.
The living polymers are conveniently prepared by contacting
the monomer with an alkali metal hydrocarbon or alkoxide salts
in the presence o~ an inert organic diluent which does not
participate in or inter~ere with the polymeriæation reactlonJ
Those monom~rs susceptible to anionic polYmerlzation
are well-known and the present invention contemplat.cs the use
of all anionically pqlymerizable monomersO Non-limiting il-
lustrative spécies include vlnyl aromatic compounds, such as
styrene, alpha-methylstyrene, vinyl toluene and its isomer$,
vlnyl unsaturated amides such as acrylamide, methacrylamide,
N,N-dilower alkyl acrylamidesJ e.gO, N,N-dimethylacrylamlde;
acenaphthalene; 9-acrylcarbazole~ acrylonitrile and methacrylo-
nitrile; organic isocyanates including lower alkyl, phenyl,
lower alkyl phenyl and halophenyl lsocyanates, organic dilso-
cyanates including lower alkylene, phenylene and tolylene di-
isocyanates, lower alkyl and allyl acrylates and methacrylates,
including methyl, t-butyl acrylates and methacrylates; lower
olefinsg such as ethylene, propylene, butylene, isobutylene,
pentene, hexene, etcO; vlnyl esters o~ aliphatic carboxylic
acids such as vinyl acetate~ vinyl propionate, vinyl octoate,
vinyl oleate, vinyl stearate, vinyl ~enzoate; vinyl lower
alkyl ethers, vinyl pyrldinesg vinyl pyrrolidones; dienes ~n-
-18-
~376;~i
cluding isoprene and butadiene. The ter~ "lower" is used aboveto denote organic groups containing eight or ~ewer carbon
atomsO The pre~erred ole~inic containing monomers are con~u.
gated dienes containing 4 to 12 carbon atoms per molecule and
the v~nyl-substituted aromatic hydrocarbo.ns containing up to
about 12 carbon atomsO
Many other monomers suitable for the preparation of
the sidechains by anionic polymeri~atlon are known in the
prior art~
The initiators ~or these anionic polymerizations are
any alkali metal hydrocarbons and alkoxide salts which produce
a mono~unctional living polymer, iOe., only one end of the
polymer contains a reactive anion, Those catalysts ~ound
suitable include the h.ydrocarbons o~ lithium, sodium, or po-
tassium as representea by the formula RMe wherein Me is an al-
kali metal such as sodium, lithium or potassium and R repre-
sents a hydrocarbon radical, ~or example, an alkyl radi¢al
containing up to about 20 carbon atoms or more, and pre~erably
up to àbout eight carbon atoms, an aryl radical, an alkaryl
radical or an aralkyl radical, Illustrative alkali metal hy-
drocarbons include ethyl sodium, n-propyl sodium, n-butyl po-
tassium9 n-octyl potassium, phenyl sodium~ ethyl lithium, sec-
butyl lithium, t butyl lithium and ~ethylhexyl lithium. Sec-
butyl lithium is the preferred initiator because it has a fast
initiation which is important in preparing palymers of narrow
molecular weight distribution. It is preferred to employ the
alkali metal salts o~ tertiary alcohols, such as potassium, t-
butyl alkoxylateg when polymerizing monomers having a nitrile
or carbonyl ~unctional group.
The alkali metal hydrocarbons and alkoxylates are
either available commercially or may be prepared by known
-19 -
`~ ~
)37636
methods, such as by the reaction of a halohydrocarbon, halo
benzene or alcohol and the appropriate alkali metal.
An inert solvent generally is used to ~acilitate
heat trans~er and adequate mix~ng o~ initiator and monomer.
Hydrocarbons and ethers are the preferred solvents. Solvents
use~ul in the anionic polymerization process include the aro-
matic hydrocarbons such as benzene, toluene, xylene, ethyl-
benzene, t-butylbenzene, etc. Also suitable are the saturated
aliphatic and cycloaliphatic hydrocarbons such as n-hexane, n-
1~ heptane, n-octane, cyclohexane and the like. In addition,
aliphatic and cyclic ether solvents can be used, for example,
dimethyl ether, diethyl ether, dibutyl ether, tetrahydro~uran,
dioxane~ anisole, tetrahydropyran, diglyme) glyme, etc. The
rates o~ polymerization are ~aster ln the ether solvents than
in the hydrocarbon solvents, and small amounts o~ ether in the
hydrocarbon solvent increase the rates of polymerization.
The amount of initiator is an important ~actor in
anionic polymerization because it determlnes the molecular
weight of the living polymerO If a small proportion of initi-
ator is used, with respect to the amount o~ monomer~ the molec-
ular weight of the living polymer will be larger than i~ a
large proportion of initiator is used. Generally, it is ad-
visable to add initiator dropwise to the monomer (when that is
the selected order o~ addition) until the persistence of the
characteristic color of the org~nic anion, then add the cal-
culated amoun~ o~ initiator for the molecular weight desired.
The preliminary dropwise addition serves to destroy contamin-
ants and thus permits better control o~ the polymerization.
To prepare a polymer of narrow molecular weight dis~
tribution, it is generally preferred to introduce all o~ the
reactive species into the system at the same time. By this
-20-
1037636
.
techniqueJ polymer growth by consecutive addition of monomertakes place at the same rate to an active terminal ~roup,
without chain trans~er or termination reaction. When this i~
accomplishedJ the molecular weight of the polymer is control-
led by the ratio Q~ monomer to initiatorJ as seen from the
following representationO
Molecular Weight Moles of Monomer Molecular Weight
Of = ~ - -~ Of
Living Polymer Moles of Initiator Monomer
As it can be seen from the above formula, high con-
centrations of initiator leads to the ~ormation o~ low molecu-
lar weight polymersJ whereas, low concentrations of initiator
leads to the production of high molecular weight polymers.
The concentration of the monomer charged to the re-
action vessel can vary widely, and is limited by the ability
o~ the reaction equipment to dissipate the heat o~ polymeriza-
tion and to properly mix the resulting vlscous solutions of
the living polymer. Concentrations of monomer as high as 50%
by weight or higher based on the weight of the reaction mix-
ture can be used. However, the preferred ~onomer concentra-
tion is from about 5~ to about 25% in order to achieve ade-
quate mixing.
As can be seen from the formula above and the ~ore-
going limitations on the concentration of the monomer, the in-
itiator concentration is critical, but may be varled according
to the desired molecular welght of the living polymer and the
relative concentration of the monomer~ Generally, the initi-
ator concentration can range from about OoO01 to about 0~1
mole of active alkali metal per mole of monomer, or higher.
Preferably~ the concentration of the initiator wili be from
about 0.01 to about 0.004 mole of active alkali metal per mole
of monomer~
-21
10~7636
The temperature of the polymerization will depend on
the monomer. Generallyg the reaction can be carried out at
temperatures ranging ~rom about -100C. up to about 100Co
When using aliphatic and hydrocarbon diluents, the preferred
tempera~ure range is from about -10C. to ~bout 100Co With
ethers as the solvent, the preferred ~emperature range ~5 ~rom
about -100C. to about 100C. The polym~rization of the sty-
rene is generally carried out at slightly above room te~pera-
ture; the polymerization of al~ha-methylstyrenç prefera~ly is
carried ou~t at lower temperatures, eOg., -80C.
The preparation of the living polymer can be carried
out by adding a solution of the alk~li metal hydrocarbon ini-
tiator in an inert-organic so~ven~ to a mixture of monomer and
diluent at the desired polymer~ation temperature and allowing
the mixture to stand with or without agitation until the poly-
merization is completedO An alternative procedure is to add
monomçr to a solution of the catalyst in the diluent at the
desired polymerization temperature at the same rate that it is
being polymerized. By either method the monomer is converted
ao quantitatively to a living polymer as long as the system re-
mains free of impurities which inactivate the anionic species.
As poin~ed out above, however, it is important to add all of
the reactive ingredients together rapidly to insure the forma-
tion of a uniform molecular weight distribution to the poly~
merO
The anionic polymerization must be carried out under
carefully controlled conditions, so as to exclude substances
which destroy the catalytic effect of the catalyst or initi-
ator. For example, such impurities as water, oxygen, carbon
monoxide, carbon dioxide, and the likeO Thus, the polymeriza~
tions are generally carried out in dry equipment, using anhy-
-22-
~037636
drous reactants, and under an inert gas atmosphere3 such asnitrogen, helium~ argon~ methanç, and the like~
The above-described living polymers are susceptible
to ~urther reactions including further polymerizationO Thus,
if additionàl monomer, such as styrene, is added to the living
polymer, the polymerization is renewed and the chain grows un~
til no more monomeric styrene remainso Alternatively, if an-
other different a~ionically polymerizable monomer is added,
such as butadiene or ethylene oxide, the above-described liv-
ing polymer initiates the polymerization of the butadiene orethylene oxide and the ultimate living polymer whlch resu}ts
consists o~ a polystyrene segment and a polybutadiene or poly-
oxyethylene segmentO
A poly(styrene-ethylene) block copolymer can be pre-
pared by contacting living polystyrene with ethylene in the
presence of a compound of a transition metal of Group V-VIII
in the periodic table, e.g.~ ~itanium tetrachloride. This
technique is also applicable to the alpha-ole~ins, such as
propylene. The resulting copolymer is still a living polymer
2Q and can be terminated by the methods in accordance to the prac-
tice of the present inventionO
As noted above~ the living polymers employed in the
present invention are characterlzed by relatively uniform
molecular weight, iOe., the distribution of molecular weights
of the mixture o~ living polymers prQduced is quite narrowO
This is in marked contrast to the typical polymer, where the
molecular weight distribution is quite broad, The difference
in molecular weight distribution is particularly evident from
an analysis of the gel permeation chromatogram of commerical
O polystyrene (Dow 666u ~prepared by free-radical polymerization
and pol~styrene produced by the anionic polymerization process
-23-
~r~ Q ~
~ (~3763q~utilized in accordance with the practice o~ the present inven-
tion.
By Termination Of The Llv~ Po ymers
The living polymers herein are terminated by reaction
with a halogen-containing compound which also contains a poly-
merizable moiety, such as an ole~inic group or an epoxy or thio-
epoxy group. Suita~le halogen-containing terminating agents in-
clude: the vinyl haloalkyl ethers wherein the alkyl groups
contain six or fewer carbon atoms such as methyl, çthyl, pro-
pyl, butyl, isobutyl, sec-butyl,~-amyl or hexyl; vinyl esters
or haloalkanoic acids wherein the alkanoic acid contains six or
~ewer carbo~ atoms, such as acetic/ propanoic, butyric, penta-
noic, or hexanoic acid; alefinlc halides haring six or fewer
carbon atoms such as vinyl halide, allyl halide, methallyl
halide, 6-halo-1-hexene, etc.; halides of dienes such as 2~
halomethyl-1~3-butadiene, epihalohydrins, acrylyl and metha-
crylyl halides, haloalkylmaleic anhydrides; haloalkylmaleate
esters; vinyl haloalkylsilanes; vinyl haloaryls; and vinyl
haloalkarylsJ such as vinylbenzyl chloride (VBC); haloalkyl
norbornenes, such as bromomethyl norbornene, bromonorbornane,
and epoxy compounds such as ethylene or propylene oxide. The
halo group may be chloro, fluoro, bromo, or iodo; pre~erably,
it is chloro. Anhydrides of compounds having an olefinic
group or an epoxy or thioepoxy group may also be employed,
such as maleic anhydride, acrylic or methacrylic anhydride.
The ~ollowing equations illustrate the typical termination re-
actions in accordance with the practice o~ the present inven-
tion:
-24-
~03763~
Livin~; Polymer:
Rl R
R--CH2~ ~ C----C~2 - C(3 + L~
R2 n R2
Te rminat ing A~;ent s;
( a ) X_ R3 _O--p = CH2
R4
(b) X~ R3--C--O--C 5 CX2
( c ) X_R3_C = CH2
R4
/\
( d ) X--R3-- CH CH2
,0,
( e ) X~ C ,C = CH2
( f ) X__ R C C~
2û (g) X--R3--Cj--CoOR3
R4~ C- CooR3
(h) ~R-- SiRR,C CH?
3~ = CH2
-25 -
1~376:~
PH2 = C - C _, CH2
R ;F,l
(a) R~ - CH2 - C ~ ~ C--R3 OC = CH
R2 Irl R2
r
t 2 , ~ C~C--R--C~OC = CH
~ Rl_
1~ ~ c ) R ~ - CH2 C,----C~2 - C . R3--C = CH2
_ R2 r~ ~2 R4
(d~ R~GH2 C~CH~ ,C R C ~2
R2 n ~2 R4
,1 o
~e) R--CH2 C ~CH2_ C ~ . C--C = CH2
_ R2 , n R2 R4
r Rll Rl
(f) R--~H2 C -- CH2~ C R3C ~ CO
2û _ R2 ,n R2 R4C~C~
_ 1- ¦ R
g ) R--CH~ C I CH2. C--R3 Cj ~COOR2
_ R2 n 3R2 ~4--C--COO R2
-26,
~37~3$
Rl I
(h) R - -CH2 - C - r CH~ C R3 - SiRRC = CH2
R2 n R2 R4
Rl- ~,1
(i) R~H2--C~CH2~ ' CH2
CH2
R Rl CH
(j) R - -CH C - CH2- C - CH2 - ,C,
_ R2_ n ~2 CH2
In the above equations, R) R1, R2J R3 and R 4 are
each selected from the group consisting o~ hydrogen and lower
alkyl, and aryl radicals, Preferab~y, R will be lower alkyl,
such as sec-butyl; Rl will be either hydrogen or methyl; R2
will be phenyli R3 will be hydrogen or lower alkylene radi.cal;
and R4 will be either hydrogen or lower alkyl radical, The
symbol n i8 a positive integer such that the properties of the
polymer are manifestJ i,e., a value such that the polymer wlll
have a molecular weight in the range of ~rom about 5,000 to
about 50~000, preferably a molecular welght in the range of
from about 10,000 to about 35jO00~ more preferably a molecular
weight in the range o~.from about 12J 000 to about 25,000.
Termination o~ the living polymer by any o~ the above
types o~ terminating agent~ is accom~lished simply by adding
the terminating agent to the solution of living polymer at the
temperature at which the living polymer is prepared. Reaçtion
is immediate and the yield is theoretical. A slight molar ex-
cess o~ the terminating agent~ with respect to the amount of
-27-
r~
~03~;~i36
catalystg m~y be used although the reaction proceeds on a
mole-~or-mole basisO
The te~mination may be conducted in any suitable in-
ert solvent. Generally, it is advisable to utilize -the same
solvent system employed in the preparation of the ll~lng poly-
mer. A preferred embodiment of thç inventlon comprises con-
ducting the termination reaction in a hydrocarbon solvent
rather than the polar ether type solvents such as tetrahydro-
furanO It has been found that the hydrocarbop solvents such
as the aromatic hydrocarbons, saturated aliphatic and cyclo-
aliphatic hydrocarbons cause several differences in the reac-
tion conditions and the resulting product. For example, the
termination reaction can be conducted at higher temperatures
with hydrocarbon solvents as opposed to the ether solvents.
In some instances, because of the nature of the liv-
ing polymer and the monomer from which it is pr,epared, or be-
cause of the nature of the terminating agent, certa~;-deleter
ious side reactions occur which result in an impure product.
For example, the carbanion of some living polymers have a ten-
dency to react with functional groups or any active hydrogensof the terminating agent. Thus, for example, acrylyl or meth-
acrylyl chloride while they act as terminating age~ts because
o~ the presence of the chlorine atom in their structure, they
also provide a carbonyl group in the terminated polymer chain,
and this carbonyl group may provide a center for attack by a
second highly reactive living polymer, The resulting polymer
either has"twice the expected'molecular weight or contains
some chlorine, indicating that some of the living polymer has
been terminated by reaction with a second living polymer or
with one of the active hydrocarbons of the acrylyl or metha-
cryly] chloride,
-28-
~03763~
It has been discovered that one means for overcoming
the foregoing problem is to render the reacti~e carbanion less
susceptible to reaction with the functlonal groups or any ac~
tive hydrogens of a terminating agentO A preferred method to
render the living polymer less susceptible to the adverse reac-
tion is to "capt' the highly reactive living polymer with a
lesser reactive reactantO Examples of some ~referred "capping
agents" include the lower alkylene oxides, io eO ~ one having
eight or fewer cairbon atoms such as ethylene and propylene
oxide; diphenyl ethylene, etc. The "capping" reaction yields
a product which still is a living polymerg but yields a purer
product when subsequently reacted with a termlnat~ng agent
contalning a ~unctional group or active hydrogenO
It ha~ been ~ound that diphenyl ethylene is an ex-
cellent "capping agent" when terminating agents such as, for
example9 vinyl chloroalkanoates are employedO
A particularly preferred "capping agent" is an
alkylene oxide, such as ethylene oxideO It ~eac~s with the
living polymer, with the destruction of its oxirane ringO The
following is a typical illustration of the "capping reactionN
whlch shows the reaction of ethylene oxide as a capping agent
with a living polymer prepared by the polymerization of sty
rene with sec-butyl lithium as theiinitiatoro
sec-~u~ E2C ~ CH ~ Li + CH2/GH2~sec-~u ~ ~ ~ CH ~ -CH2CH2~ ~i
The capping reaction is carried out quite simiply, as
in the case o~ the terminating reaction, by adding the capping
reactant to the living polymer at polymerization temperatures.
The reaction occurs immediately. As in the case of the termin-
-29~
~L03~;3E;
ation reaction, a slight molar excess of the capping reactant
with respect to the amount of initiator may be used. The re-
action occurs on ~ mole-for~mole basis.
It will be understood that when a large molar excess
o~ alkylene oxide is reacted with the living polymer, a living
polymer having two polymeric blocks is producedO A typical
example with polystyrene segments and polyoxyalkylene segments
is illustrated as ~ollowsO
sec-Bu ~ H ~ ~ CH ~ CH2CH20)x _ CH2CH20 + Li
wherein x is a positive integer.
Either of the above-described ethylene oxide t'capped"
polymers can be conveniently terminated with a compound con-
taining a moiety reactive with the anion o~ the c~pped polymer
and a polymerizable end group9 including the following typical
compounds. acrylyl chloride, methacrylyl chloride~ vinyl-2-
chloroethyl ether, vinyl chloroacetate, chloromethylmaleic an-
hydride and its esters, maleic anhydride (yields-half ester of
maleic acid following protonation with water), allyl and meth-
allyl chloride and vinylbenzyl chloride.
The reaction of the above-described "capped living
polymers with either acrylyl or methacrylyl chloride can be
represented by the following reaction~
-3
~l~)3763~
CH =`C-C-Cl
sec~R~ ~ 2 ~ ~ (CH2CH20)x~~~2C~20 + Li R4
' i
.,
F ~2 ~ ~ (cx2cH2o)x--cN2cH2occ = CH2 ~ L1Cl
wherein n is a positive integer of about at least 509 x is
either 0 or a positive integer and R is either hydrogen or
methyl~
When an epihalohydrin is used as the terminating
reagent, the resulting polymer contains a terminal epoxy group.
This terminal epoxy may be used as the polymerizable group it-
self, such as in the preparation of a polyisobutylene or a
polypropylene oxide backbone graft copolymer or may be con-
verted to various other use~ul polymerizable e~d groups by any
one of several known reactions.
As one embodiment of the invention9 the terminated
polymer containing an epoxy or thioepoxy end group may be re-
acted with a polymerizable carboxylic acid halide, such as
acrylic, methacrylic, or maleic acid halide, to produce a beta-
hydroxyalkyl acrylate, methacrylate or maleate ester as the
polymerizable terminal moiety of the substantially uniform
molecular weight polymer. These same polymer~xa~le esters ~ay
be prepared from the terminal epoxy p~lymer by first convert-
ing the epoxy group to the corresponding glycol by warming the
polymer with aqueous sodium hydroxide, followed by convention-
al esterification of the glyco~ end group with the appropriate
-31-
~37~i36
polymerizable carboxylic acid, or ~cid halideO
The resulting glycol obta~ned by the aqeuous hydrol-
ysis o~ the epoxy group in the pr~sence o~ a baæe may be con-
verted to a c~po4ymer by reaction with,a high molecular weight
dicarboxylic acid which may be prepared, e.g., by the polymer-
ization of a glycol or diamine with a mol&r excess of phthalic
anhydrideJ maleic anhydrideJ succ~nic anhydride, or the like.
These reactions can be modified to obtain a polystyrene block
and a polyamide block (Nylon), The glycol terminated polymer
may also be reacted with a diisocyanate to form a polyurethane
The diisocyanate may be e.g., the reaction product of a poly-
ethylene glycol having an average molecular weight of 400 wlth
a molar excess of phenylene dilsocyanateO
In another embodiment of the invention, an organic
epoxide is copolymerized with a terminated polymer containing
an epoxy or thioepoxy end group, The graft copolymer which
results is characterized by a backbone having uninterrupted
segments of at least about 20, and preferably at least about
30, recurring units of the organic epoxide. Preferred organic
epoxides include ethylene oxide, propylene oxide, butylene
oxide, hexylene oxide, cyclohexene epoxide and styrene oxide,
i.e., those having 8 or ~ewer carbon atoms.
When a haloalkylmaleic anhydride or haloalkylmaleate
ester is used as the terminating age~t, the resulting terminal
groups can be converted by hydrolysis to carb~xyl gro~psO The
resulting dicarboxylic polymer may be copolymerized with
glycols or diamines to form polyesters and polyamides having a
graft copolymer structureO
If it is desired to isolate and further puri~y the
macromolecular monomer from the solvent from which it was pre-
pared, and of the known techniques used by those skillecl in
-32-
1037636
the art in recovering polymeric materials may be u~ed. These
techniques includeO (1) solvent-non-solvent precipltation;
(2) evaporation of solvent in an aqueous media, ~nd (3) evapo-
ration of solventJ such as by vacuum roll drying, spray dr~y-
ing~ freeze drying, and (4) steam jet coagulation~
The isolation and recovery of the macromolecular
monomer is not a critical feature of the invention In ~act,
the macromolecula~ monomer need not be recovered at all~
Stated otherwise, the macromolecular monomer, once ~ormed, can
be charged with the suitahle monomer and polymeriza~ion cata-
lyst to conduct the graft copolymerization in the same system
as the macromolecular monomer was prepared, providing the sol-
ve~t and materials ln the macromolecular monomer preparation
reactor do not poison the catalyst or act in a dele~erious man-
ner to the graft copolymerieation process. Thus~ a ~udicious
selection of the solvent and purification of the reactor system
in the preparation of the macromolecular monomer ca:n ultimate-
ly result in a large savings in the production of the graft
copolymers of the present invention.
As pointed out above, the maçromolecular monomers~
which ultimately become the sidechains of the gra~t copolymers
by being integrally polymerized into the backbone polymer, must
have a narrow molecular weight distribution. Methods ~or de-
termining the molecular weight distribution o~ polymers such
as the macromolecular monomers are known in the art. Using
these known methods, the weight average molecular weight (Mw)
and the number average molecular weight (~n) can be ascertain-
ed~ and the molecular weight distribution (Mw/~n) for the
macromolecular monomer can be determinedO The macromolecular
monomers must have nearly a Poisson molecular weight distribu-
tion or be virtually monodisperse in order to have the highest
-33-
~3763~
degree of ~uncti~nality~ Preferably, the ratio of ~w ~ o~the novel macromolecular monomers will be less than about 1. lo
The macromolecular monomers of the prçsent invention possess
the aforementioned narrow molecular weight distribution and
purity due to the method of their preparat;ion~ described here-
inabove. Thusg it is important that the sequence o~ step~ ln
preparing the macromolecular monomers be adhered to in order
to produce the optimum results in beneficial properties in the
graft copolymers.
Prior to the invention herein, gra~t copol~mers were
prepared by synthesizing a linear ~backbone") then grafting
onto this backbone, growing polymeric or preformed polymeric
chains. These methods generally re~uire elaborate equipment
and produce a mixture of products having inferior properties
unless further puri~i.ed~ Because o~ the additional processing
conditions and the use of special equipment, these proce~ses
are not economically feasible.
Although some of the prior art graft copolymers re-
semble the gra~t copolymers of the present invention, neuer-
theless generally, the present graft copolymers are differentcompositions, not only because they are prepared by signifi~ ;
cantly di~ferent processes, but because the pendant polymeric
chains of the graft copolymers of this invention are of rela-
tively uniform, minimum length, and are each an lntegral part
o~ the backbone, Furthermore~ the backbone o~ the graft co-
polymers o~ the present invention contain polymeric segments
of certain minimum length. Thus~ the present graft copolymers
differ structurally because the macromolec~lar monomer is
interposed between polymeric segments of the backbone polymer,
rather than being merely attached to the backbone polymer in
a random manner. These characteristics contribute materially
-34-
~ 37636
to the advantageous propertles which inhere in these novel
graft copolymers.
The graft copolymers of the present invention are
prepared by first synthesizing the pendant polymeric chains
~the polymerizable terminated living polymers) then copolymer-
izing the terminal portions of the polymeric chains with the
second monomer during the formation of the backbone polymer.
In accordance with the practice of the present in-
vention, the substantially pure macromolecular monomers of
high controlled molecular weight and mol~Gular weight distribu-
tion have an appropriate reactive end group suitable for any
mechanism of copolymerization, e.g,, ~ree-radical, cationic,
anionic, Ziegler catalysisJ and condensa~ion. Thus, the re-
actlve end group is selected ~or easy copolymerizatlon with
low cost monomers by conventional means and within existing
polymerization equipment.
The copolymerization with the macromolecular mono-
mers and the secand reactive monomer is a gra~t-like structure
where the pendant chain is a polymer whose molecular weight
and distribution are predetermined by independent synthesis.
The distribution of the sidechain polymer along the backbone
is controlled by the reactivity ratios of the comonomers.
Since the reactive end group of the macromolecular
monomer is copolymerized with the second monomer, it is an in-
tegral part of the backbone polymer. Thus, the polymerizable
end group o~ the macromolecular monomer is interposed between
large segments of the backbone polymer.
The present invention provides a means ~or control-
ling the structure of the graft copolymer. More specifically,
the control of the structure o~ the gra~t copolymer can be ac-
complished by any one or all of the following means: (1) by
-35-
~376;~
determining the reactivity ratio of the macromolecular monomerand a second monomer during the copolymerization reaction, a
pure graft polymer free from contamination by homopolymers can
be prepared~ (2) by controlling the monomer addition rates dur-
ing the copolymerization o~ a macromolecular monomer and a sec-
ond monomer, the distance between the sidechains in the poly-
mer structure can be controlled; and (3) the size of the graft
chain can be predetermined and controlled in the anionic poly-
merization step o~ the preparation of the macromolecular mono-
mer.
It will be apparent to those skilled in the art that
by the proper selection o~ terminating agents, all mechanisms
o~ copolymerization may be employed in preparing the controlled
phase separated gra~t copolymers.
As alluded to hereinabove, the chemically joined,
phase separated graft copolymers o~ the present invention are
pre~erably copolymerized with any ethylenically-unsaturated
monomer including the vinylidene type compounds containing at
.1
least one vinylidene CH2 = C - group and preferably the vinyl-
type compounds containine the characteristic CH2 = CE- group
wherein hydrogen is attached ~o one o~ the free valences of
the vinylidene group. The copolymerization, as pointed out
above, is only dependent upon the relative reactivity ratios
of the terminal group and the comonomerO
Examples of some of the preferred ethylenically-un-
saturated compounds used as the comonomers include the a~rylic
acids, their esters, amides and nitriles including acrylic
acid, methacrylic acid, the alkyl esters ~f acrylic and meth-
acrylic acid, acrylonitrile, methacrylonitrile9 acrylamide,methacrylamide, N,N-dimethacrylamide (NNDMA); the ~inyl
-36-
~037~3~i
halides such as vinyl chloride, and vinylidene chloride; the
vinyl cyanides such as vinylidene cyanide (l,l-dicyanoethyl-
ene); the vinyl esters of the fatty acids such as vinyl ace-
tate, vinyl propionate and vinyl chloroacetate, etcO; and the
vinylidene containing dicarboxylic anhydrides, acids and
esters, such as maleic and ~umaric anhydride, acids or esters
thereofO
A particularly important class of vinylidene type
compounds useful as comonomers with the alpha-olefin and sty-
rene terminated macromolecular monomers include the vinyl ole-
finic hydrocarbons, such as ethylene, propylene, l-butene~ iso-
butylene~ l-pen~ene, l-hexene, styrene, 3-methyl-1-butene, 4-
methyl-l-hexene and cyclohexene~ Also, there may be used as
the comonomers the polyolefinic materials containing at lea~t
one vinylidene group such a~ the butad~ene-1,3 hydrocarbons
including butadiene, isoprene, piperylene and other conjugated
dienes, as well as other conjugated and non-conjugated poly-
ole~inic monomers including divinyl benzene, the diacrylate
type esters of methylene, ethylene, polyethylene glycols, and
polyallyl sucroseO
The most preferred ethylenically unsaturated comono-
mers are the commercially available and widely used monomers
such as methyl acrylate, butyl acrylate, 2-ethyl hexyl acry-
late, methyl methacrylateJ vinyl chloride, vinylidene chlo-
ride, vinylidene cyanide, acrylonitrile, and the hydrocarbon
-monomers such as ethylene, propylene, styrene, and the con~û-
g~ted dienes such as butadiene and isopreneO
In addition to the hereinabove described ethylenic-
ally-unsaturated comonomers use~ul in the practice of the in-
vention, there are included the comonomers capable of copoly-
merizing by condensation or step reaction polymerization con-
-37-
~037636
ditions with the polymerizable macromolecular monomer~ o~-the
invention~ In this connection, the polymerizable macromolecu-
lar monomers w~11 contain the appropriate terminal groups ne-
cessary to ~acilitate the condensation reactionO For example,
living ~olymers terminated with eplchlorohydrin will contain
OH OH
an epo~y tenminal group w~ich co~verts to a CH- CH2 group
upon saponification. This vicinal hydroxy group is capable of
copolymerizing with polybasic acids and anhydrides to ~orm
polyesters, such as adiplc acid, phthalic anhydride, maleic
anhydride, succinic anhydride, trimellitic anhydride, etc.;
aldehydes to form polyacetals, such as polg~ormaldehyde, u~ea-
formaldehydesg acetaldehydes, etc.; polyisocyanates and poly-
lsocyanate prepolymers to ~orm polyurethanes3 and siloxanes to
~orm polysiloxanesO The living polymers terminated with
halomaleic anhydride or halomaleate ester may be converted to
terminal carboxyl groups by conventional hydrolysisO The re-
sulting dicarboxylic terminated po}ymer can be copolymerized
with glycols to form polyesters or with diamines to form poly-
amides having a graft copolymer structure. Alternatively, themaleic anhydrlde or ester terminal group or the polymer can be
used ln the candensation polymerization with the glycols or
diamines. ~he vicinal hydroxy or carboxyl terminated pol~mers
of the invention can also be copo1ymerized with epoxy c~m-
pounds, and the imine compounds, such as ethylene~mineO
The placement of the sidechain in the polymer back-
bone is dependent on the terminal group o~ the macromolecular
monomer and the reactivity of the comonomer~
The macromolecular monomers of the invention are
stable in storage and do not significantly homopolymerize,
Furthermore, the macromolecular monomer copolymerizes through
-38-
~)3763~
the terminal double bond or reactive end group and is not in-
corporated into the polymeric back~one by grafting reactions
to the polymer o~ the macromolecular monomer segment.
As indicate4 hereinabove, the macromolecular mono-
mers of the invention copolymerize with commercial vinyl mono-
mers in a predictable manner as determined by relative reac-
tivity ratios. It can be shown that the instantaneous copoly-
mer equation:
lQ (1~ dM1 ~ Mll rrlMl ~ 2
L ~ L 1 + r2
simply ~educes to ~he approximation:
(2) d 1 ~ M1
when ~ is in very low molar concentra~ion~.
Thus~ the macromolecular monomer (Ml) copolymerizations with
other monomers (M2) are described only by r2 values and mono-
mer feed compositions. Rearra~gement of equatio~ (2) gives:
~3) dM2/M? % Conversion M2
2 dMl/Ml ~ ~Convërsion Ml
The reactivity ratio~ r2~ can be estimated ~rom a
relatively low conversion sample o~ a single copolymerization
experiment. The validity of this con~ept of a predictable and
controllable reactivity o~ the macromolecular monomer can
thereby be established. It has been shown that the re~ctivity
of ¢ommerçial monomers with the macromolecular monomers of the
present invention with vàrious end groups correlate with avail-
able literature values for reactivity ratios of r2,
The method of the present invention permits the
-39
~)37636
utilization o~ all types o~ polymerizable monomers ~or incor-
poration into backbone polymers, and makes it poss~ble ~or the
~irst time to design and build gra~t copolymers of controlled
molecular structure, and of backbone and gra~t segments with
di~erent properties, such as hydrophobic and hydrophilic seg-
ments, crystalline and amorphous segments~ polar and non-polar
segments, segments with widely di~ferent glass transition tem-
peratures, whereas prior work on SDA terblock copolymers had
been limited to the incompatibility of glassy polystyrene
blocks with rubbery polydiene blocks.
The cDpolymerization o~ the polymerizable macro-
molecular monomers with the comonomers may be conducted in a
wide range o~ proportions. Generally spea~ing~ a suf~icient
amount o~ the macromolecular monomer should be present to pro-
vide the chemically ~oining of at least one of the uniform
molecular weight sidechain polymers to each backbone polymer,
so that a noticeable ef~ect on the properties o~ the graft
copolymeric properties can be obtained. Since the molecular
weight of the polymerizable macromolecular monomer generally
exceeds that of the polymerizable comonomers, a r~latively
small amount o~ the polymerizable macromolecular monomer can
be employed, However, the chemically ~oined, phase separated
thermoplastic graft copolymers may be prepared by copolymer-
izing a mixture containing up to about 95% by weight, or more,
of the polymerizable macromolecular monomers of this inven-
tion, although mixtures containing up to about 60% by weight
of the polymerizable macromolecular monomer are preferred.
Stated otherwise, the resinous thermoplastic chemically joined,
phase separated graft copolymer of the invention is comprised
o~ (1) from 1% to about 95~ by weight of the polymerizable
macromolecular monomer having a narrow molecular weight clis-
-40~-
1~37636
utilization of all types of polymerizable monomers for incor-
poration into backbone polymers, and makes it possible for the
first time to design and build graft copolymers of controlled
molecular structure, and of backbone and gra~t segments with
different properties, such as hydrophobic and hydrophilic seg-
ments, crystalline and amorphous segmentsg polar and non-polar
segments, segments with widely different glass transition tem-
per~tures, whereas prior work on SDA terblock copolymers had
been limited to the incompatibility of glassy polystyrene
blocks with rubbery polydiene blocks.
The copolymerization of the polymerizable macro-
molecular monomers with the comonomers may be conducted in a
wide range of proportions. Generally speakingg a sufficient
amount of the macromolecular monomer should be present to pro-
vide the chemically joining of at least one of the uniform
molecular weight sidechain polymers to each backbone polymer,
so that a noticeable effect on the propertles of the graft
copolymeric properties can be obtained. Since the molecular
weight of the polymerizable macromolecular monomer generally
exceeds that of the polymerizable comonomers, a r~latively
small amount of the polymerizable macromolecular monomer can
be employedO ~owever, the chemically joined, phase separated
thermoplastic graft copolymers may bè prepared by copolymer-
izing a mixture containing up to about 95~ by weight, or more,
of the polymerizable macromolecular monomers of this inven-
tion, although mixtures containing up to about 60~ by weight
of the polymerizable macromolecular monomer are pre~erred.
Stated otherwise, the resinous thermoplastic chemically joined,
phase sqparated graft copolymer of the invention is comprised
of (1) from 1~ to about 95% by weight of the polymerizable
macromolecular monomer having a narrow molecular weight clis-
-40~-
-
~,o3763~ , .
tribution (iOeO~ a Mw/~n o~ less than about lol)g and ~2) from
99% to about 5~ by weight o~ a copolymerizable comonomér de-
~ined her~inabove.
The polymerizable macromolecular monomers copoly-
merize with the hereinabove re~erred to comonomers in bulk, in
solution, in aqueous suspension and in aqueou~ emulsion systems
suitable for the particular pol~merizable macromolecular mono-
mer, its end group and the copolymer employedO I~ a catalyst
is employed, the polymerization environment suitable ~or the
catalyst should be employed. For example~ oil- or solvent-
soluble peroxides such as benzoyl peroxldes, are generally ef-
fective when the polymerizable macromolecular monomer is co-
polymerized with an ethylenically unsaturated comonomer in
bulk~ in solution in an organic solvent such as benzene, cyclo-
hexane, hexane, toluene, xylene, etc. 9 or in aqueous suspen-
sion, Water~soluble peroxides such as s~dium9 pqtassium9
lithium and ammonium persul~ates) etc. are use~ul ln aqueous
suspension and emulsion systemsO In the copolymerization o~
many o~ the polymerizable macromolecular monomers, such as
those with an ethylenically-unsaturated end group and a poly-
st~rene, polyisoprene or polybutadiene repe~ting unit, an
emulsi~ier or dispersing agent may be employed in aqueous sus-
pension systems~ In these systems, particular advantage can
be achieved by dissolving the water-insoluble polymerizable
macromolecular monomer in a small amount of a suitable sol-
vent, such as a hydrocarbon. By this novel technique, the co-
monomer copolymerizes with the polymerizable macromolecular
monomer in the solvent, in an aqueous system surrounding the
solvent-polymer system. 0~ course, the polymerization cata-
lyst is chosen such that it will be soluble in the organicphase of the polymerization systemO
~41-
~03763$
As previously stated, various di~ferent catalyst
systems can be employed in the present invention ~or the co-
polymerization processO It will be apparent to those skilled
in the art that the particular catalyst sy~tem used in the co-
polymerization will vary, depending on the monomer feed and
the particular end group on the macromolecular monomerO For
example, when using a macromolecular monomer having a vinyl
acetate end group, best results are generally obtained by em
ploying free-radical catalyst systemsO On the other hand, co-
polymerization u~ilizing isobutylene monomer feed with eitheran allyl, methallyl or epoxy terminated macromolecular mono-
mer, best results are accomplished by utilizing the cationic
polymeri,zation techniques, Since the particular polymerizable
end group on the macromolecular monomer will depend on the co-
monomer feed employed because of the relative reactivity ra-
tio:sJ the polymerization mechanism commonly employed for the
particular comonomer will be used. For example, ethylene poly-
merizes under free-radical, cationic and coordination polymer-
ization conditions; propylene and higher alpha-olefins only
polymerize under coordination polymerization conditions; iso-
butylene only polymerizes under cationic polymer~z~tion condl-
tions; the dienes polymerize by free-radical anionic and co-
ordination polymerizatian conditions; styrene polymerizes
under free-radical, cationic, anionic and coordination condi-
tions; vinyl chloride polymerizes under free-radical and co--
ordination polymerization conditions, vinylidene chloride
polymerizes under free-radical polymerization conditlons;
vinyl fluoride polymerizes under free-radical conditions;
tetra~luoroethylene polymeri~es under ~ree-radical and co-
ordination polymerization conditions; vinyl ethers polymerizeunder cationic and coordination polymerization conditions;
-4?-
-
~376;~6
vinyl esters polymerize under free-radical polymerization con-
ditions, acrylic and methacrylic esters polymerize under free-
radical, anionic and coordination polymerization condi~ions,
and acrylonitrile polymerizes under free-radical3 anionic and
coordination polymerization conditionsO
It will be understood by those skilled in the art
that the solvent9 reaction conditions and feed rate will be
partially dependent upon the type of catalyst system utilized
in the copolymerization process, One of the considerations, - 10 of course, will be that the macromolecular monomer be dis-
solved in the solvent system utilized. It is not necessary,
however, ~or the monomer feed to be soluble in the solvent
system, Generally, under these conditions during the forma-
tion o~ the copolymer, the graft copolymer will precipitate
out of the solvent wherein it can be recovered by techniques
known in the polymer artO
The temperature and pressure conditions during the
copolymerization process will vary according to the type of
catalyst system utilized. ThusJ in the production of low den-
sity polyolefin backbones under free-radical conditions, ex-
tremely high pressures will be employed. On the other hand,
the high density substantially linear polyolefin backbone
polymers produced by the coordination type catalyst generally
will be prepared under moderately low pressures.
When preparing graft copolymers having a poly41efin
backbone of ethylene or propylene or copolymers of ethylene
and propylene together with a macromolecular monomer, it is
preferred to employ a coordination catalyst known in the art
as the Ziegler catalyst and Natta catalysts (the latter being
commonly used for polypropylene). That is, materials ad~
vanced by Professor DrO ~arl Ziegler of the Max Planck
-43-
10376,~6
Institute of Mulheim, Ruhr, Germany, and Dr. Giulio Natta o~
Milan, Italy~ These catalysts are prepared by the interaction
of a compound of transition metals of group IV-VIII in the
periodic table, the catalyst, and an organometallic compound
derived from group I-III metals~ as co-catl~lyst. The latter
are compounds such as metal hydrides and alkyls capable o~
giving rise to hydride ions or carbanionsJ such as trialkyl
aluminum. Compounds of the transition elements have a struc-
ture with incomplete d-shells and in the lower valence states,
can associate with the metal alkyls to ~orm complexes with
highly polarlzed bonds. Those elements hereinabove re~erred
to as the catalysts are pre~erably titanium, chromium, vana-
dium, and zirconlum. They yield the best Ziegler catalysts by
reaction of their compounds with metal alkyls.
Compounds Or these transition metals in the higher
valence stage, e.g., titanium tetrachloride, are reduced by
the metal alkyls to a lower valence state. The reswltant prod-
ucts containing the transition metal in the lower valence
~t~te, e.g., titanium dichloride, react directly with the
metal alkyl to yield active catalysts possessing hydride ions
or car~anions. If the reduction of the transition metal com-
pound proceeds to the ~ree metal, the resultant products are
either suitable for catalysis of the displacement reaction,
e.g~, nickel, cobalt, platinum, or an active polymerization
catalyst.
Also included among the coo~dination catalysts con-
templated for the copolymerization process of the present in-
vention are those catalyst systems comprising a compound of
one or more of the elements o~ titaniuml zirconium, cerium,
vanadium, niobium, tantalum, chromium, molybdenum or tungsten,
wherein at least a part o~ the metal is present in a valence
-44-
~ i3~;state of three or below and preferably two3 or is associatéd
with a su~ficient quantity of a reduci~g agent capable of re-
ducing the valence state o~ the polyvalent metal to such a
lower state, Suitable reducing agents include Grignard re~ -
agents, metal alkyls or aryls, zinc metal and metals above
zinc in the electromotive series, and the metal hydrides.
As is well-kn~wn, the Ziegler catalysts which are
e~fective for the polymerization of ethylene to linear, high
density, high molecular we~ght polyethylene, and the stereo-
specific polymerization of other al~ha-olefins to crystalline,
stereoisomeric polymers are g~nerally heterogeneousO
The various Ziegler catalysts referred to above are
approximately equally capable of polymeriæing either ethylene,
higher ~le~-olefins, such as p~opylene, 1-butene, isobutylene,
l-pentene, l-hexene, styrene, 3-methyl-1-butene and 4-methyl-
l-hexene and conjugated diolefins such as butadiene and iso-
prene. They can also be used in the copolymerization o~ any of
these monomers with ethylene and other al~ olefins in con-
junction with the macromolecular monomers of the present in-
vention. The difference between the polymerization of ethyl-
ene and that o~ alpha-olefins lies in the possibility of at-
taining structural regularity in higher polyolefins.
Genera~ly speaking, the production of the high den-
sity graft copolymers having olefin backbones will be conduct-
ed at pressures of ~rom about 1 to about 1,000 pSiJ preferably
from about 1 to 200 psi~ The pressure may be increased by the
use of nitrogen gas, i~ desired.
As previously stated, the solvent system utilized
will most conveniently be the solvent employed ln the prepara-
tio~ of the macromolecular monomer. Solvents useful for thepolystyrene macromolecular monomers are those which dissolve
-45-
103763~
'
polystyreneO Typical solvents for polystyrene include cyclo-
hexane, benzeneg toluene, xylene, decalin, tetraling etcO
The copolymerization reaction may be conducted at
any suitable temperature9 depending on the particular cata-
lyst, macromolecular monomer, monomer feed~ resulting graft
copolymer and solvent usedO Generally, the graft copolymeriza-
tion will be conducted at a temperature of from about 10Co to
about 500C., preferably from about 20C. to about 100C.
The gra~t copolymeri~ation rqaction is pre~erably
conducted by placing a predetermined amount of the macromo
lecular monomer dissolved in the appropriate solvent in the
reactorO The polymerization catalyst and monomer are there-
after fed into the solvent system to produce the gra~t co-
polymer.
It is generally desirable to provide a graft co-
.polyme~ having at least about 2~ macromolecular monomer incor-
porated in the backbone polymeric material, however, satis-
factory results can be obtained wlth up to about 40% by weight
macromolecular monomer lncorporationO Preferablyg the gra~t
copolymers of the present invention will have about 5% to
about 20% by weight incorporation of the macromolecular mono-
mer into the backbone polymeric material to obtain the opti-
mum physical properties of both the sidechain polymer and the
backbone polymerO However, graft copolymers having up to
about 95% by weight of the macromol~cularri~onomers incorporat-
ed therein may be prepared and are contemplated within the
scope of the inventionO
~ he means for providing the proper amount of incor-
poration of the macromolecular monomer can be determined simply
3Q by adding the appropriate weighed macromolecular monomer used
in the copolymerization processO For example, i~ a graft
-46-
~L~3763i~
copolymer having 10~ by weight incorpo~ation of the macro~molecular monomer into the backbone polymer is desired, one
simply employs 10 parts by welght of the macromolecular mono-
mer for each 90 partæ by weight of the monomer feedO
Following the procedures ~ d above, graft co-
polymers having unique combinations o~ properties are ~roducedO
These unique combinations of properties are made possible by
the novel process herein which forces the compatibility of
~otherwise incompatible polymeric segmentsO These in~mpatible
segments segregate into phases of their own kind.
The chemieally joined, phase separated gr~t copoly-
mers of the invention microscopically possess a controlled
dispersion of the macromolecular sidechain in one phase
(domain) within the backbone polymer phase (matrix). Because
all of the macromolecular monomer sidechaln domains are an in-
tegral part or interposed between large segments of the back-
bone polymer, the resulting graft copolymer will have the
properties of a cross-linked polymer, if there is a large dif-
ference in the Tg or Tm of the backbone and sidechain segmentsO
~his is true only up to the temperature required t~ break the
thermodynamic cross-link of the dispersed phase, I~ ~ssense,
a physically cross-linked (as opposed to chemical cross-linked)
type polymer can be made that is reprocessable and whose prop-
erti~3. are established by simple cooling~ rather than vulcan-
ization or chemical cross-linkingO
The graft copolymers of the present invention are '
differentiated from the macroscopic opaque and weak blends of
incompatible polymers of the prior art. The graft copolymers
of this invention contain separate phases which are chemically
joined and the dispersion of one segment into the ma-trix poly~
mer is on a microscopic l~yel and below the wavelength of
-47-
~ - .
~ 0~7636
copolymer having 10% by weight incorporation of the macro-
molecular monomer into the back~one polymer is desired, one
simply employs 10 parts by weight of the macromolecular mono-
mer for each 90 parts by weight o~ the monomer ~eedO
Following the procedures ~tlin~d above, gra~t co-
polymers having unique comblnations o~ properties are ~roducedO
These unique combinations o~ properties are made poss~ble by
the novel process herein which forces the compatibility of
otherwise incompatible polymeric segments. These ~n~Pmpatible
segments segregate into phases of their own kind.
The chem~cally joined, phase separated graft copol~-
mers of the invention microscopically possess a controlled
dispersion o~ the macromolecular sidechain in one phase
(domain) within the backbone polymer phase (matrix)~ Because
all of the macromolecular monomer sidechain domains are an in-
tegral part or interposed between large segments of the back-
bone polymer, the resulting graft copolymer will have the
properties of a cross-linked polymer, if there i9 a large di~-
~erence in the Tg or Tm of the backbone and sidechain segments.
This is true only up to the temperature required to break the
thermodynamic cross-link of the dispersed phaseO I~ ~ssense,
a physically cross-linked (as opposed to chemical cross-lin}ced)
type polymer can be made that is reprocessable and whose prop-
~erties are established by simple cooling~ rather than vulcan-
ization or chemical cross-linkingO
The graft copolymers of the present invention are ' -
differentiated from the macroscopic opaque and weak blends of
incompatible polymers of the prior artO The graft copolymers
of this invention contain separate phases which are chemically
~oined and the dispersion of one segment into the matrix poly-
mer is on a microscopic leyel and bel~w the wavelength of
-47-
~03763~:i
light of the matrix polymer. The gra~t copol~mers herein are,
thereforeg transparent9 tough, and truly thermoplasticO
An illustrative exa~ple of the present invention in-
cludes combining the advantageous properties of polystyrene
with the advantageous properties of polyethylene, although
these two polymers normally are incompatible with one another
and a mere physical mixture of these polymers has very little
strength and is not usefulO To combine these advantageous
properties in one product, it is necessary that the different
polymeric segments be present as relatively large segmentsO
The properties of polystyrene do not become apparent until
the polymer cQnsists essentially of at least about 20 r~ul~
ring monomeric units. This same relationshlp applies to the
polymeric segments present in the gra~t copolymers herein,
i.e.J i~ a graft copolymer comprising polystyrene se~ments is
to be characterized by the advantageous properties of poly-
styrene, then those polystyrene segments must9 individually9
consist essentially of at least about 20 recurring monomeric
units. This relationship between the physical properties of
a polymeric segment in its minimum sige is applicable to the
polymeric segment of all graf~ copolymers herein. In general,
the mlnlmum size of a polymeric segment which is associated
with the appearance of the physical properties of that polymer
in the graft copolymers herein is that which consists of about
20 recurring monomeric units. Preferably, as noted earlier
herein, the polymeric segments both of the copolymeric back-
bone and the sidechainsg will consist essentially of more than
about 30 recurring monomeric unitsO However, as it is well-
known, the highly beneficial properties of polymers such as
polystyrene are generally apparent when the polymer has a m~-
lecular weight of from about 5,000 to about 50JOOO9 preferably
-~8-
~D3763~6
from about 10,000 to about 35gO00, more preferably 12gO00 toabout 25~000O
The polymeric segments of the graft copolymers of
the invention may themselves be homopolymeric or they may be
copolymericO Thusg a graft copolymer of this invention may be
prepared by the copolymerization o~ ethylene, propylene, and a
terminated polystyrene containing a polymerizable alPha-ole~in
end groupO The uninterrupted polymeric segments of the back~
bone of such a graft copolymer will be copolymeric segments of
ethylene and propylene.
The graft copolymers comprising polymeric segments
having ~ewer than about 20 recurring monomeric units areg
nevertheless, useful for many applications, but the preferred
gra~t copolymers are those in which the various polymeric seg-
ments have at least about 20 recurring monomerlc unitsO
Although, as indicated, the gra~t copolymers herein
are charactbrized by a wide variety o~ physical properties,
depending on the particular monomers used in their preparation,
and also on the molecular weights of the various polymer seg-
ments within a par~ular graft copolymer, all o~ these gra~tcopolymers are useful, as tough, flexible, self-supporting
films, The~e ~ilms may be used as ~ood-wrapping m~terial~
painters' dropcloths, protective wrapping for merchandise dis-
played for sale9 and the likeO
Gra~t copolymers of the macromolecular monomer9
polystyrene, wlth ethylen~-propylene, isobutylene9 or propyl-
ene oxide monomers have been found to be stable materials that
behave like vulcanized rubbers, but are thermoplastic and re-
processable~ Thus9 an extremely toughg rubbery plastic is ob-
tained without the inherent disadv~ntages of a vul~anizedrubber. These copolymerized rubber-~orming monomers with the
-49-
~037S3~ci
macromolecular monomers of the present invention have the ad-
ditional use as an alloying agent for dispersing additional
rubber for impact plasticsO
Just as metal properties are improved by alloyingy
so are polymer propertiesO By adding the appropriate amount
of an incompatible material to a plastic in a microdispersed
phase~ over-all polymer properties are improvedO A s~all
amount of incompatible polybutadiene rubber correctly dispersed
in polystyrene gives high impact polystyrene. The ke~ to this
microdispersion is a small amount of chemical graft copolymer
that acts as a flux for incorporating the incompatible rubb~r.
In a similar mannerJ a copolymer o~ the macromolecu~
lar monomer of the present lnvent~on can be the ~lux for in-
corporating or dispersing incompatible polymers into new
matrices making possible a whole new line of alloys, impact
plastics, malleable plastics, easy-to-process plasticsq
The use of the graft copolymers as alloying agents
is particularly e~emplified in the case of polyethylene-poly-
styrene blendsO As it is well-knQ,wnJ polyethylene and po~y-
styrene are incompatible when blended together. However~ whenusing the graft copolymers of the present invention as an
alloying agent, the polyethylene and polystyrene phases can be
conveniently ~oined.
For example, a blend prepared by mixing 90 to 51
parts by weight o~ commercial polyethylene ~either low or
high density), 10 to 49 parts by weight of com~ercial poly-
styrene and 5 to 30 parts by weight of a graft copolymer of
the present invention comprising polystyrene sidechains and a
polyethylene backbone are useful in making automobile parts,
such as inner door panels~ kick panelsg and bucket seat backs~
or appliance parts such as television components. Such blends
-5o
~3763!6
are also useful as structural foams, sheets and films, con-
tainers and lids in packaging9 beverage cases9 pails, in the
manufacture of toys~ molded sheets ~n furniture9 hot mold ad-
hesives and computer and magnetic tapes.
The use of the graft copolymers of the present in-
vention as an alloying agent offers a distinct advantage over
the prior art blends9 ~asmuch as the plastic blend can be
processed with minimized phase separation of the polyst~rene
and polyethylene polymers in the blendO The strength of the
novel blends of the present invention is also ~mproved over
the blends of the prior art~
If polystyrene in the macromolecular mono~er is re-
placed by a poly(alpha-methylstyrene) and is copolymerized
with ethylene9 a similar polyblend can be prepared as describ-
ed above, However, these blends will have heat stability
which will allow the resulting plastics to be use~ul in making
hot water pipes, sheets in warm areas, and automobile parts,
having oxidative stability over rubber-containing materials.
These plastics also have utility in preparing reinforced
fiberglass and fillers due to their good adhesion to fiber-
glass. Polyblends of poly(alpha-methylstyrene) graft copoly-
mer with large amounts, i.e.~ 51-90~ by weight of poly(alpha-
methylstyrene) and 10-49% polyethylene, exhibit a higher heat
distortion9 together wlth high impact strength and high modu-
luso These plastics are useful in various engineering applica-
tions and in the manufacture of parts for aircraft, auto
bodies9 recreational vehlclesg appliancesg gearsg bearings,
etcO
Another useful blend utilizing the graft copolymers
of the present invention comprises mixing 10 to 49 parts of
low density polyethylene9 51 to 91 parts by weight of poly-
-51~
.
~)37~i3~
(alpha~methylstyrene) and zero to 30 parts by weight o~ poly-
styrene and 5 to 30 parts by weight of the gra~t cop.olymer of
the present invention comprising polyethy:lene backbone with
poly(alpha-methylstyrene) or styrene sidechains. The blend
is extruded in a Imill and the resultant plastic is found use-
ful in making appliances such as co~fee makers, humidifiers,
high intensity lamps, color television setsJ kitchen-range
hardware, blenders, mixers, and electric toothbrushes. These
plastics are also useful in preparing recreational ~ehicles
such as snowmobile parts and helmets, machine parts such as
gears, bearings; plumbing pàrts such as shower heads, ~alves~
fittings and ballcocks; and motor housing, stamping, lawn
sprinklersg stereo tape or cartridges, etc.
The rein~orcement o~ plastics by adding glass fibers
or other materials is difficult to achieve because of poor
wetting character of many basic polymersO The macromolecular
monomers of the present invention, particularly those contain-
ing reactive polystyrene, have a tendency to wet and bond to
glass with facility, By proper dispersion o~ glass in a
macromolecular copolymer, it is possible to upgrade the bond
between the dispersed phase and glass. Thus, the macromoleçu-
lar graft copolymers o~ the present invention can also be used
as reinforcing adhesion aids to glass fibers~
The invention is illustrated further by the ~ollow-
ing examples which, however, are not to be taken as limiting
in any respectO In each case, all materials should be pure
and care should be taken to keep the reacted mixtures dry and
free of contaminantsO All parts and percentages~ unless ex-
pressly stated to be otherwise, are by wei~t.
-52-
~037636
Preparation 0~ Macromolecular Monomer
ular Weight
EXAMPLE 1
. ~ , ~
(a) PreParation ~ Pol~st_r~ n~ With All,yl Chloride:
A sta~nle~s steel reactor is charged with 76~56 parts
of A~Co5~ grade benzene (thiophene-free), which had been pre-
dried by Linde molecular sieves and calcium hydrideO The re-
actor is heated to 40Co and 00015 parts of diphenylethylene
is added to the reactor by means of a hypodermic s~ringeO A
0 1201% ~olution o~ sec-butyl lithium in hexane iB added to the
reactor portionwise until the retention of a permanent orange-
yellow color9 at which point an additional o.885 parts (1.67
moles) of sec-butyl lithium solution is addedJ followed by the
addition of 22,7 parts (218 moles) of styrene over a period of
44 minutesO The reactor temperature i8 maintained at 36-42Co
The living polystyrene is terminated by the addition of Oo 127
parts of allyl chloride to'`the reaction mixture. 'The result-
ing polymer is precipitated by the addition of the alpha-
olefin terminated polystyrene-benzene solution into methanol,
whereupon the polymer precipitates out of solution, The
alpha-olefin terminated polystyrene is dried in an air circu-
lating atmosphere drier at 40-45~C~ and then in a ~luidized
bed to remove the trace amounts of methanol. The methanol con-
tent after purification is 10 parts per millionO The molecular
weight of the polymer, as determined by membrane phase osmo-
metry~ is 15,400 (theory: 13,400) and the molecular weight
distribution is very narrow, iOeO~ the Mw/Mn ls less than 1~05.
The macromolecular monomer has the following structural .
formulaO
,~
~037~3~i
CH3CH2(C~3)CH CH2~CH - _ CH2 -CH = C~2
_ ~ In
wherein n has a value such that the molecular weight of the
polymer is 15,4000
(b) The procedure of Example l(a) is repeated using~
in place o~ allyl chloride, an equivalent amount of methallyl
chloride to produce a metha~lyl terminated polystyreneO
(c) The procedure of paragraph (a) is repeated using,
in place o~ styrene, an equivalent amount of ethylene oxide to
produce a crystalline polyoxyethylene living polymerO The
living polymer is terminated by the addition o~ a molar equiva-
lent amount o~ vinylbenzyl chloride to produce a pol~mer hav-
ing the following structural formula:
CH3CH2(C~3)C~ ~ CH2CH2 ~ CH2 ~ CH - CH2
n
EXAMPLE 2
(a) Prepara~tion 0~ Pol,Y-(-alpha-met-hry-l-s~t-~yrene) Terminated With
All~L ChlorideO
A solution o~ 472 grams (4.0 moles) of ~le~_-methyl-
styrene in 2500 ml. of tetrahydrofuran is treated dropwise
with a 12% solution o~ n-butyl lithium in hexane until the
persistence of a light red color. An addltional 30 mlO
(oOo383 mole) of this n~butyl lithium solution is added, re-
sulting in the development o~ a bright red color. The tempera-
ture o~ the mixture is then lowered to -80C., and a~ter 30
minutes at this temperature3 4.5 grams (o.o6 mole) of allyl
chloride is added. The red color disappears almost immedi-
ately9 indicating termination o~ the living polymerO The re-
sulting colorless solution is poured into methanol to precipi-
-54-
~03763i
tate the alpha-ole~in terminated poly(alPha-methylstyrene)
which is shown by vapor phase osmometry to have a number
average molecular weight of 11~000 (theoryo 12,300) and the
molecular weight distribution is very nar:row9 iOeO~ the ~w/Mn
is less than 1.05O The macromolecular monQmer produced has
the following structural formula:
CH3
CH3CH2C~2C~12 tCH2_C~ C~2CH = CH2
wherein n has a value such that the molecular weight o~ the
polymer is 11,000.
The procedure of paragraph (a) is repeated using~ in
place o~ n-butyl lithium, a solution of an equivalent amount
of potassium t-butyl alkoxylate and in place of ~ -methyl-
styrene9 an equivalent amount respectively of:
(b) 4-vinyl pyridine, terminatihg with a molar equiv-
alént of allyl chloride to produce a polymer having the follow-
ing structural ~ormula:
(CH3)3 C--0 _CH2--CH _ CH2CH = CH2;
_ ~ _ n
(c) methacrylonitrile, terminating with a molar equiv-
alent of vinylbenzyl chl~ride to produce a polymer having the
following structural formula-
r CH3
(CH3)3 C - O - -CE~ C - CH2 ~ CH = CH2 ;
. CN .
n
-55-
~()376;~
(d) methyl methacrylat~9 terminating with vinylbenzyl
chloride to produce a polymer having the ~ollowing structural
~o~mulaO
CH3
(CH3)3 C - O - -CH2 C - CH~ ~ C~ = CH2
C=O
_ OCH3 n
(e) N,N-dimeth~lacrylamide~ terminating with p-
vinylbenzyl chloride ~o produce a pol~mer having the following
structural formulaO
(CH3)3 - C ~ 2 , ~ CH ~ CH = CH2
C = O
_ N(CH3)2, Ln
EXAMPLE 3
Preparation 0~ Polystyrene
Terminated With Vinvl Chloroacetate
A solution of one drop o~ diphenyl ethylene in 250Q
ml. o~ cyclohexane at 40C. is treated portionwise wlth a 12%
solution of sec-butyl lithium in cyclohexane until the per-
sistence o~ a light red color~ at which point an additional 18ml. (0.024 mole) o~ the sec-butyl lithium is addedg followed
by 312 grams (3.0 moles) of styrene. The temperature of the
polymerization mixture is maintained at 40C. for 30 minutes,
whereupon the living polystyrene is capped by treatment with 8
ml. (00040 mole) of diphenyl ethylene, then terminated by
treatment with 6 ml. (0.05 mole) o~ vinyl chloroacetate~ The
resulting polymer is precipitated by addition of the cyclo-
hexane solution to methanol and the po~ymer is separated by
~iltration. Its number average molecular weight9 a~ deter-
-56~
~ ~3763$
mined by vapor phase osmometry9 is 129000 ~theory~ 13,265)3
and the molecular weight distribution is very narrow9 ~eO~
the ~w/Un is ~ess than lu060 The macromo:Lecular monomer pro-
duced has the following structural formula:
~ ..
CE3C~2(C~3)c~c~2--~j CH ~--C~2COCH = CH2
wherein n has a value such that the molecular weight of the
polymer is 12,000.
EX~MPLE 4
Preparatio~ ~f Pol,y~alpha-met~lst~ e)
Terminated With Vinyl Chloroacetate
A solution of 357 grams (300 moles) of al~_-methyl-
styrene in 2500 ml. o~ tetrahydrofuran is treated dropwise
with a 12% solution of t-butyl lithium in pentane until the
persistence of a light red color. Thereupon, an additional
15.0 mlO (0-.03 mole) of the t~butyl solution is added, result-
ing in the development of a bright red color. The temperature
of the mixture i5 then lowered to -80Co and after 30 minutes
at that temperature, 5.6 ml. of diphenyl ethylene is added~
The resulting mixture is poured into 5~0 ml. (0.04 mole) of
vinyl chloroacetate and the thus-terminated poly(alpha-methyl~
styrene) is precipitated with methanol and separated by filtra-
tionO Its number average molecular weight, as determined by
vapor phase osmometry9 is 14,280 (theory: 12,065) and the
molecular weight distribution is ~ery narrowO The macromolecu-
; lar monomer produced has the following structural formulaO
-57
,
~03763~i
r CH31 ~o
CH3C~2(C~3)CH ~ L2--~ ~ N ~--CE2CCOCH = Cl2
wherein n has a value such that the molecular weight of the
polymer is 14,280~
EXAMPLE 5
Pre~aration Of Polystyrene Terminated
With Vinyl-2-Chloroeth21_~ther
A solution o~ one drop o~ diphenyl ethyle~e at 40C.
is treated portionwise with a 12% solution of t-butyl lithium
in pentane until the persistence of a light red color, at
which point an additional 30 ml, (0,04 mole) of the _-butyl
lithium solution is added, followed by 312 grams (3~0 moles)
of styrene. The temperature of the ~olymerization mixture is
maintained at 40Co ~or 30 minutes, whereupon the living poly-
styrene is terminated by treatment with 8 ml. (o.o8 mole) of
vinyl-2-chloroethyl ether. The r~sulting polymer is precipi-
tated by addition of the benzene solution to methanol and the
polymer is separated by filtration. Its number average molecu-
lar weight, as determined by vapor phase osmometry, is 7,200(theory: 7,870) and the molecular weight distribution is very
narrow, i.e., the Mw/Mn is less than 1. o6. The macromolecular
monomer produced has the following structural formula:
)3c - - CH CH- ~ ~2C~20CH = CH2
- ~- in
wherein n has a value such that the molecular weight of the
polymer is 7,200.
-58-
37635
EXAMPLE 6
.. ... . . .
Preparation Of Polystyrene Termi ated With E~ichlor ~ in
A benzene solution of living polystyrene is prepared
in Example 5 and terminated by treatment with 10 grams (OolO
mole) of epichlorohydrinO The resulting term~nated polysty-
rene is precipitated with methanol and separated by filtra-
tion. Its molecular weight, as s~own by vapor phase osmometry,
is 8, 660 (theory~ 7,757) and its nu~er average molecular
weight distribut~on is very narrow. The macromolecular mono-
mer produced has the ~ollowing structural formu~a:
~CH3)3 C ~ CH~---CH ~ / \
L ~ J n
wherein n has a value such that the molecular weight of the
polymer is 8,660.
EXAMPLE 7
(a) Preparation Of Polystyene Terminated With Methacrvl.
Chloride:
To a solution of 0. 2 ml. o~ diphenyl ethylene in
2500 mlO of benzene there is added dropwise a 12~ solution of
n-butyl lithium in hexane until the persistence of a light
reddish-brown color. An additional 24 mlO (0~031 mole) of
this n-butyl lithium solution is added, and then, 416 grams
(4.0 moles) of styrene, resulting in the development of an
orange color. A temperature of 40C. is maintained throughout
by external cooling and by controlling the rate at which the
styrene is added. Th~s ~emperature is maintained for an addi-
tional 30 minutes after all of the styrene has been added, and
then is lowered to 20Co~ whereupon 4O4 grams (Ool mole) of
ethylene oxide is addedJ causing the solution to hecome color-
-59-
~37~3~i
lessO The living polymer is terminated by reaction with 10
ml. (Ool mole) o~ methacrylyl chloride. The resulting poly-
mer has a number average molecular weight as shown by vapor
p~ase osmometry o~ 10,00~. The macromolecular monomer has the
; following structural ~ormula- -
_ _
CH3CH2CH2CH2 - 2 1 CH2C~2CC = CH2
_ ~ CH3
wherein n has a value such that the molecular weigh~ of the
polymer is 10,000.
(b) Acrylyl chloride is substituted ~or methacrylyl
ch}oride in the above procedure to give an acrylic acid ester
end group on the polystyrene chain.
(c) Allyl chloride is substituted ~or meth~crylyl
chloride in procedure (a) to produce an allyl ether terminated
polystyrene.
(d) Methallyl chloride is substituted for methacrylyl
chloride in procedure (a) to produce methallyl ether terminated
polyætyreneO
(e) Maleic anhydride is substituted ~or methacrylyl
chloride in procedure (a), ~ollowed by protonation with water
to produce polystyrene terminated with the hal~ este~ o~
maleic acid.
(~) Epichlorohydrin is substituted ~or methacrylyl
chloride to produce an epoxy ether terminated polystyreneO
(g) The procedure of (a) is repeated uslng in place
o~ styrene, an equivalent amount of isoprene and in place of
n-butyl lithium an equivalent amount of sec~butyl lithium to
produce primarily a rubbery cis-1,4 polyisoprene~ The low Tg
living polymer is terminated by the additi~n o~ a molar equiva-
-60-
103763~
lent9 based on sec-butyl lithium, ethylene oxide as a capping
agent, followed by a molar equivalent amount of allyl chloride
to produce a polymer predominantly having the ~ollowing struc-
tural formulao
~ ~ C C / ~ 2
LCH3 H
EXAMPIE 8
.
Pre~aration Of Pol~Yst~y~r-ene
Terminated With Methacrylyl Chloride
A stainless s~eel reactor is charged with 32 gallons
o~ A,C.S. grade benzene (thiophene-free), which had been pre-
dried by Linde molecular sieves and calcium hydrideO The reac-
tor is heated to a temperature o~ between 38-40C. and 10 ml.
of diphenyl ethylene is added to the reactor by means of a
hypodermic syringe. An 11.4~ solution o~ secondary butyl lith-
ium in hexane is added to the reactor portionwise until the
retention of a permanent orange-yellow color is obtained (60
ml.), at which point an additional 3.44 pounds of the secondary
butyl lithium in hexane is added to the reactor, followed by
the addition of 8205 pounds of purified styrene over a period
of 1 hour and 40 minutes. The reactor temperature is main-
tained at 38-~0C The living polystyrene is capped by the ad-
dition of 0.28 pounds of ethylene oxide and the reaction solu-
tion changes from a red-orange çolor to yellowO The resulting
capped living polystyrene is thereafter reacted with 260 mlO
of methacrylyl chloride and the solution changes to a very pale
yellow colorO The methacrylate terminated polystyrene is pre-
3Q cipitated by the addition of the polymer benzene solution intomethanol, whereupon the polymer precipitates out o~ solution.
-61-
~13763~;
The polymer i9 dried in an air circulating atmosphere drier at40-45C. and then in a fluidized bed to remove the trace ~
amounts of methanol, The molecular weight of the polymer as
determined by membrane phase osmometry, is 13,400 and the
molecular weight distribution is very narrow, i.eO, the Mw/Mn
is less than~l.O5.
EXAMPLE 9
Preparation Of Polys~yrene
Te ~
A stainless steel reactor is charged with 2.5 liters
of A.C,S. grade benzene (thiophene-~ree), which had been pre-
dried by Linde molecular sieves and calcium hydride. The re-
actor is heated to 40C. and 0.2 ml. of diphenyl eth~lene is
added to the reactor by means of a hypodermic syringe. A 12.1%
solution of sec-butyl lithium in hexane is added to the reactor
portionwise until the retention of a permanent orange-yellow
color is obtained (0.7 ml.), at which point an addi~ional 22.3
ml. of sec-butyl lithium solution is added, followed by the ad-
dition of 421.7 grams of styrene over a period of 16 minutes.
The reactor temperature is maintained at 40-45C. Five minutes
after styrene addition is completed, ethylene oxide is added
from a lecture bottle subsurface intermittently until the solu-
tion is water white. One hour after ethylene oxide addition is
complete, 20055 ml. of maleic anhydride-benzene solution (the
maleic anhydride solution was prepared by dissolving 84 grams
of maleic anhydride in 550 grams of purified benzene) is added
to the capped living polymer. One hour after the addition of
the maleic anhydride solution, the contents of the reactor are
discharged and precipitated in methanolO The maleic half ester
terminated polystyrene had a molecular weight of about 149000,
a~ determined by Gel Permeation Chromatography. The polymer-
-62-
~376~
izable macromolecular mono~er has a structural ~ormula repre-
sen~ed as follows:
Sec-Butyl ¦CH2 ~H2~H20
HOC
o
EXAMPLE 10
Preparation Cf Polvbutadiene
Te~minated With Allyl Chloride
C.P, grade 1,3-butadiene (99.0% purity) is condensed
and collec ed in l-pint soda bottles. These bottles had been
oven baked ~or 4 hours at 150C., nitrogen purged duri~g cool-
ing, and capped with a perforated metal crown çap using butyl
rubber and polyethylene ~ilm liners. These bottles containing
the butadiene are stored at -10C. with a nitr~gen pressure
head (10 psi) in a laboratory ~reezer before use. Hexane sol-
vent is charged to the reactors and hçated to 50C., followed
by the addition of 0.2 ml. of diphenyl ethylene by way of a
syringe. Secondary butyl lithium is added dropwise via syringe
to the reactor ~ntil the red diphenyl ethylene anion color
persists for at least about 10-15 minutes. The reactor temper-
ature is lowered to 0C., and 328.0 grams of butadiene is
charged into the polymerization reactor, followed by the addi-
tion of 17.4 ml. (0.02187 mole) of a 12~ secondary butyl lith-
ium solution in hexane, when hal~ of the butadiene charge has
been added to the reactor. The butadiene is polymerized for
18 hours in hexane at 50Co Following the polymerization,
400 ml. portions of the anionic polybutadiene solution in the
reactor is trans~erred under nitrogen pressure into capped
-63-
3763~i
bottlesO Allyl chloride (oO48 mlO~ o-oos88 mole) is injected
into each of the bottles, The bottles are clamped i~ water
baths at temperatures of 50C. and 70Co for pçriods o~ time
ranging up to 24 hours. The s~mples in each o~ the bottles
are short stopped with methanol and Ionol solution and anal-
yzed by Gel Permeation ChromatographyO Each of the samples is
water white and the analysis of the Gel pe~meation Chromato-
g~aphy scans reveals that each of the samples had a narrow
molecular weight distribution.
Several comparison samples were conducted in bottles
coming from the same lot of living polybutadiene) which were
capped with 2-chlorobutane (0.4 ml., o.oo376 mole) as the ter-
minating agent. The resulting polymers terminated with 2-
chlorobutane were yellow in color and ~ter standing ~or a
period of 24 hours at 70C., appeared to have a broad molecu-
lar weight distribution as revealed by the Gel Permeation
Chromatography scan. It is clear that the reaction and reac-
tion product of 2-chlorobutane with anionic polybutadiene are
different than the reaction and reaction product of allyl chlo-
20 ride and anionic polybutadiene.
EXAMPLE 11
C Preparation ~ Methacr,~late Terminated Pol,yisoprene
A one-gallon Chemco glass-bowl reactor is charged
with 2.5 liters of purified heptane which had been preq~ied
by a Linde molecular sieve and calcium hydride, followed by
the addition of 002 ~1~ of diphenyl ethylene as an indicator
and the reactor is sterilized with the dropwise addition of
tertiary butyl lithium solution (12~ in hexane) untll the re-
tention of the characteristic light yellow color is obtained.
The reactor is heated to 40C. and 19.9 ml. (00025 mole) of a
12% solution of tertiary butyl lithium in hexane is in~ected
~rQd~m~fk -64_
~ 3~63~
into the reactor via hypodermic syringe, followed by the addi-
tion of 33104 grams (4.86 moles) of isopreneO The mixture is
allowed to stand ~or one hour at 40Co ancl 0013 mole of ethyl-
ene oxide is charged into the reactor to cap the living poly-
isopreneO The capped living polyisoprene is held at 40CO for
40 minutesJ whereupDn 0.041 mole of methacrylyl chlorlde is
charged into the reactor to terminate the capped living poly-
mer~ The mixture is held for 13 minutes at 40C~ ~ followed
by removal of the heptane solvent by vacuum strippin~. Based
upon the Gel Permeation Chromatography scans for polystyrene,
the molecular weight of the methacrylate terminated polyiso-
prene by Gel Permeation Chromatography was about 10,000
(theory: 13,000). The methacrylate terminated polyisoprene
macromolecular monomer has a structural formula repre~ented as
followsO
o
~C~3
20EXAMPLE 12
Préparation Of Alpha-Olefin Terminated Polyisoprene
_, .
~J ~ A one-gallon Chem~o glass-bowl reactor is charged
with 2,5 liters of purified heptane which had been predried by
a Linde molecular sieve and calcium hydride, followed by the
addition of 002 mlO of diphenyl ethylene as an indicator. The
reactor~and solvent are sterilized by the dropwise addition of
tertiary butyl lithium solution (12% in hexane~ until the re-
tention of the characteristic light yellow color is obtained.
The reactor is heated to 40Co and l9o 03 mlO (Oo 02426 mole) of
30 tertiary butyl lithium solution is in~ected into the reactor
~ dQ~r k -65-
~ 11~763~i
via hypodermic syringe3 followed by the addltion of 31505
grams (4~63 moles) of isopreneO The polymerizatio~ is per~
mitted to proceed at 50Co for 66 minutes and at th~s time 20 0
ml. (0002451 mole) o~ allyl chloride is added to the living
polyisoprene. The terminated polyisoprene is held at 50Co
for 38 minutes, whereupon the polymer is removed from the
reactor to be used in copolymerization reactionsO The polymer
was analyzed by Gel Permeation Chromatography and had a very
narrow molecular weight distribution, iOeO> an MwjMn of less
~han about 'lo o60 The theoretical molecular weight of the
polymer is 1390000 The polymerizable macromolecular monomer
has a structural formula represented as ~ollows:
~H3CH2~CH3)CH ~ C ~ ~ CH2 ~ H2 CH = CH2
/C = C\
_CH3 H
EXAMPLE 13
C ~ Polymerization Of Styrene With Vinyl Lithium
To a one gallon Chemco~reactor, there is added 2500
ml. of tetrahydro~uran and cooled to 15~C., at which time 6.5
mlO of a 11.2~ solution of vinyl lithium in tetrahydrof~lran
(0.2 mole lithium) is added to the reactor, imparting a light
tan color to the solution. The vinyl lithium was purchased
from Alpha Inorganics Ventron of Beverly, Massachusetts, as a
two molar solution in tetrahydrofuranO Analysis of the solu-
tion by several methods showed that the solu-tion contained
llo 2~ active lithiumO After the vinyl lithium solution is
added, a 0025 mole styrene charge is added to the reactor via
syringe with the observation of a small exotherm q~ about
1Co (the reactor temperature is controlled by liquid nitrogen
cooling coils inslde the reactQr at a temperature o~ 15C.).
~ 66-
l~rc~d~ k
~03763~
Ten minutes afrer the styrene is addedg 306 ml. of water is
added to the reactor, resulting in an almost immediate change
in color from deep orange brown to water white and a consider-
able gas evolution is observed ~the internal pressure in the
reactor increased from 8 psig to 12 psig)" A sample is taken
from the head space (about 20 5 liters ln volume) and from the
liquid phase at the same time (the two samples are analyzed
and identified as containing largè amounts of ethylene). The
styrene polymer is withdrawn from the reactor and analyzed.
The GPC molecular weight o~ the polystyrene is 108gOOO~ as
measured against the Pressure Chemical Company sample 2tb)
standard certi~ied as Mw/Mn = 1~06g Mw = 20,800 ~ 800 and Mn =
20,200 ~ 600. Measured against the same standard, the weight
average molecular weight of the po~ymer is 99gOOO and the
number average molecular weight is 66,oooO The polydisper-
sity of the polymer i8 1.49~ Based upo~ the limiting poly-
dispersity of about 1.33 for living p~lymers, several side
reactions obviously occur when using vinyl lithium as a poly-
merization inltiatorO In addition, the broad molecular weight
distribution and the inability to control the molecular weight
of the polymer is indicative that the initiation rate of vinyl
lithium is e.xtremely slowO Accordingly, the vinyl lithium
initiated polystyrene is not suitable in the preparation of
the graft copolymers of the present invention in preparing
chemically ~oinedg phase separated graft copolymersg which
have sidechains of controlled and uniform molecular we~gh~sO
Attempted copolymerization of the vinyl lithium in-
itiated polystyrene with methyl methacrylate and acrylonitrile
under free-radical conditions only results in a mixture of
polystyrene and the respective poly(methyl methacrylate) or
polyacrylonitrile~ AlSOg attempted copolymerization of the
-~7-
1~3763~
alpha-olefin terminated polystyrene of Example l(a) with
methyl methacrylate and acrylonitr'~le under free-radical
conditions only resulted in a mixture of homopolymers as de
termined by IR analysis of the benzene and cyclohexane ex-
tractsO This result is expected due to the inability of
alPha-olefins to polymerize under free-radical conditionsO
Preparation 0~ Graft Co,pol~ers ~ving Macromolecular
EXAMPLE 14
Prepàration Of Graft Copol,ymer From Pol,v(al~h~,-methylstyrene)
Macromolecular ~onomer Terminated With Allyl Chloride And
., .
h.Ylene
A solutlon of 20 grams of poly(alpha-methylstyrene)
macromolecular monomer terminated with allyl chloride and hav-
ing an average molecular weight of 10,000 prepared as in Ex-
ample 2(a) in 100 ml. of cyclohexane is prepared and treated
with 5.5 ml. of oO645 M (901% solution) dlethyl aluminum chlo-
ride in hexane and 2 ml. of vana~ium oxytrichloride, then
pressured with ethylene to 3,0 psig. This system is agitated
gently ~or about one hour at 30C.~ whereupon a polymeric
material precipitates from the solutionO It i.s recovered by
filtratiQn and pressed into a thin transparent film which is
tough and flexibleO
EXAMPLE 1~
(a) Preparation Of Graft Copol,ymer Havin A :Pol,yeth,ylene Back-
~
One gram of the alpha-olefin terminated polystyrene
of uniform molecular weight prepared in Example lta) is dis-
solved in 1500 mlO of cyclohexane and charged into a 2-liter
"Chemco" reactor. The reactor is purged with prepuri~ied ni-
trogen for 30 minutes9 and 22 mlO of 25% ethylaluminum sesqui-
-68
~0376~6
chloride solution (in heptane) is added. The reaction i9
pressured to 40 psi with 20 grams of ethylene into the solu-
tion. Thereafter~ Ool mlO of vanadium oxytrichloride is added
and the ethylene pressure drops from 40 psi to 1 psi in about
1 minuteO The reaction is terminated in 3 minutes by the ad-
dition of isopropanolO The polymer is recovered by flltration
and slurried with cyclohexane and then with isopropanolO The
yield is 18.0 grams of a ~luffy, white copolymer having a
macromolecular monomer sidechain content ~ 508%, as deter-
mined by I~Ro Extraction and analysis of the extracts ~ndi-
cate all of the macromolecular monomer and 17~0 grams of the
ethylene copolymerized.
(b) The procedure in Exa~ple 8(a) is repeated, ex-
cept that 200 grams of the macromolecular monomer is used in-
stead of 1.0 gramO The yield of the copol~mer is 2005 grams
and the macromolecular monomer sidechain content, as deter-
mined by IoRo~ is 10%.
EX~MPLE 16
(a) Preparation Of Gra~t Copoly~er Having A Pb~_thylene
Backbone And Polvstyrene Sidechains:
A 2-liter "Chemco" reactor is charged with 1500 ml.
of purified cyclohexaneO 20 Grams of alpha-ole~in terminated
polystyrene prepared in Example l(a) is added and dissolved
in the puri~ied cyclohexaneO The reactor is thereafter purged
with prepurified nitrogen for one hour with concurrent slow
agitation. Ethylene is added to the reactor at the rate of 5
liters per minute to a pressure of 5 psio The contents of the
reactor is heated and controlled at 25Co,and high speed stir-
ring is started, ethylaluminum sesquichloride ~22.8 mlO~ 25%
in heptane) catalyst is injected into the reactor by a hypo-
dermic syringe, followed by the addition of 0.1 ml. of vanadium
-69-
~3763~i
oxytrichloride. Polymerization begins immediately a~d theethylene pressure in the reactor drops to nearl~ zero in about
a minute. At this point, the ethylene rate is reduced to 0
liter per minute, and cooling is used to maintain a ~empera-
ture of 25Co At the-end of one hour~ a total of 43 grams of
ethylene has been charged into the reactor, and the reactor is
full of a fluffy polymer slurryO The reaction i5 stopped by
the addition of 50 mlO of isopropanol to inactivate the cata-
lyst,
The polymer is recovered by filtration, slurried and
boiled in 1. 5 liters of benzene for one h~ur, then re-filtered
to remove all the unreacted alpha-olefin terminated polysty-
- ~ J' rene from the copolymer. The polymer is then slurried in lo 5
liters of isopropanol and 0.03 gram of Irganox~1010 antl-
oxidant is added and then filtered and dried in a vacuum oven
at 50CC. The yield is 49 grams of a M~ffy, white copolymer
having an alpha-olefin terminated polystyrene content o~ 16%,
as determined by I.R. of a pressed film.
(b) Preparation Of Graft Copolymer Having A Pol~eth~lene Back-
bone An~ Pol~(alpha-meth~lst~rene) Sidechains.
The macromolecular monomer used to produce the side-
chains is first prepared by repeating ~he procedure described
in Exanple 2(a), except that in place of the n-butyl lithium,
14 ml. (0,0178 mole) of sec-butyl lithium (12% solution in
heptane) is used as the initiatorO The number average molecu-
lar weight, as determined by gel permeation chromatography, is
26,000 (theory: 26,500) and the molecular weight distribution
is very narrow, iOeO~ the Rw/Mn is less than 1.05.
Four liters of cyclohexane ~Phillips polymerization
grade) and 200 grams of the alpha olefin terminated poly(alPha
methylstyrene) macromolecular monomer produced as described
rr~dt ~a rk ~7~
~3763~i
above are charged into a "ahemco" reactorO The mixture is
heated to 70Co with concurrent Stirring~ to dissolve the
macromolecular monomer, The reactor is purged with high pur-
ity nitrogen ~or one hour with stirr~ngO Ethylene gas is in-
troduced into the reactor to a pressure o~ 5 psi, followed by
228 mlO o~ ethylaluminum sesquichloride ~25~ in heptane) and
lo O mlO vanadium Qxytrichloride. Agitat~on is increased and
polymerization begins immedi~tely, as noted by the pressure in
the reactor dropping to nearly ~ero. The ethylene ~low rate
10 is ad~usted to 5 liters per minute, and the internal tempera- ;
ture is controlled at 70Co At the end o~ one hour, the re-
action i8 terminated by the addition o~ 500 mlO o~ isopropanol
to inactivate the catalystO
The polymer is isolated by centrifugation, slurried
with benzene for one hour, and recentrifugedO The copolymer
is then slurried in 5 liters o~ methanol and 0.3 gram o~
Irganox 1010 for one hour, centrifuged and dried in an oven at
50C. The yield is 260 grams having an alpha-ole~in terminat-
ed poly(alpha-methylstyrene) content of 22~, as determined by
I,R. analysis o~ a pressed film.
EXAMPLE 17
Preparation 0~ Graft Copol~ avin~ An Ethylene-
Prop!ylene Copolymeric Backbone And Polystyrene Sidechains
A 2-liter "Chemco" reactor is charged with lz liters
o~ dry benzene and 50 grams of poly(alpha-methylstyrene) ter-
minated with allyl chloride (as prepared in Example 2). The
macromolecular monomer i$ dissolved by stirring and thereafter
purged with nitrogen. The reactor is then charged with ethyl-
ene and propylene gases at the rate o~ 200 ml./minute and 800
ml./minute~ respectively, to build-up lO psi pressure in the
reactorO While maintaining a reaction temperature of 25-30C,~
-71-
~3763~
2 mlO of vanadium oxytrichloride and 4 mlO of ethylaluminum
sesquichloride solution (25% in heptane) are added to the re-
action mixture by means o~ syringe to initiate polymerizationv
As the polymerization is started, additional macromolecular
monomer (335 mlO of 10% macromolecular solution) is added in
solution formJ iOeO~ 70 grams of the macromolecular monomer is
dissolved in 630 mlO of dry benzene, and pumped in by Micro-
Bellow-pump. During the reaction9 the flow rate o~ the gases
are checked constantly to insure that the ethylene and propyl-
1~ ene ~eed rate are at the same initial levelO Additional cat-
alyst, Et3 A12 C13 (27 mlO in 25% heptane) and VOC13 (108 mlO)
is added by syringe during the reaction, as the rate of poly-
merization slowed down, which is observed by a build-up of the
internal pressure in the reactor. A~ter one hour, the poly-
merization is terminated by the additlon o~ 20 mlO o~ opro-
pyl alcoholO The product is precipitated in methanol and 51
grams of a white9 rubbery polymer is obtainedO
EXAMPLE 18
Preparation Of Gra~t CopolYm~r Having Ethylene-
Propylene Copolvmeric Backbone And Polyst~rene Sidechains
A l-gallon "Chemco" reactor is charged with 3 liters
of dried cyclohexane and 10 grams o~ polystyrene terminated
with allyl chloride (as prepared in Example l)o The solution
is pur~ed with nitrogen for 30 minutesO 20 Ml. o~ tri-n-
hexylaluminum (25%)solution is added, followed by the addition
of 139~5 grams of propylene to obtain a pressure of 26 psi and
2004 grams of ethylene to obtain a pressure of 48 psio Finally
there is added 0.2 ml. of vanadium oxytrichloride and a drop
in pressure i~ observedO The polymerization is terminated
after 10 minutes by the addition of 10 mlO of isopropanolO
The terpolymer solution is added slowly, wi-th stir~
-72-
` ~3763Çi
ring, to a 4-liter beaker containi~g methanol to coagulate the
polymer. The polymer which separated is air dried overnightO
To remove the trace of catalyst residue, the gray colored
polymer is dissolved in 500 mlO of cyclohexane and placed in a
2-liter resin flaskg together with 1 liter of distilled water
containing Ool gram of NaOH9 and refluxed at 80Co for 2
hoursO The contents are transferred into a 2-llter separatory
funnel, and the bottom water layer is drainedO The upper
cyclohexane layer is added to methanol slowly, with stirring,
to coagulate the polymer. The recovered polymer ls dried in a
vacuum ovenO The unreacted macromolecular monomer is removed
from the dried polymer by first dlssolving in cyclohexane and
adding dropwise to methyl ethyl ketone, with stirringO The
terpolymer which is insoluble in methyl ethyl ketone is fil-
tered and dried in a vacuum ovenJ and a yield of 52 grams is
obtained. The terpolymer has improved tensile strength com-
pared to ethylene-propylene copolymers prepared in the same
manner without the macromolecular monomer.
EXAMPLE 19
PreParation Of Graft Co~olymer Havin~
PolYlsoprene Backbone And Pol~Ystyrene Sidechains
500 Ml. of dried cyclohexane is charged into a re-
actor, followed by the addition o~ 100 mlO (68 grams) of
freshly distilled isoprene (Phillips polymerization grade),
together with 17 grams of polystyrene terminated with allyl
chloride (as prepared in Example l)o The reactor is sealed,
followed by the additiQn of 2.5 mlO of tri-n-hexylaluminum
solution (25% in heptane) and 0016 mlO of titanium tetra-
chloride with hypodermic syringesO The reactor is agitated
at 55Co for 16 hours, whereupon the contents of the reactor
are slowly poured, with stirring, into a 4-liter beaker con-
-73-
76;~i
taining 2 liters of a 1% solution of Ionol antioxidant in iso-
pr~panol. A tough, ru~bery, copolymer is obtained.
EXAMPLE 20
Preparation 0~ Gra~t Copol~mer Havin~ A Polvstyrene
Backbone And Polyoxyethylene Sidechains
Equal parts o~ the polyoxyethylene terminated with
vinylbenæyl chloride prepared in Example l(b) and styrene mon-
omer are placed in a reactor containing 1,000 mlO o~ benzene.
The reactor is heated to 60C. and one part by weight of azo-
bisisobutyronitrile ~ree-radical polymerization catalyst is
added. The polymerization is complete in three hours, ob-
taining a graft copolymer having hydrophilic-hydrophobic
properties. The gra~t copolymer also reduces hydrostatic
charges ~nd is an allo~Ying agent for polystyrene and pol~oxy-
ethylene.
EXAMPLE 21
Prepara~ion Of Graft Copolymer Havin A
PolyPropylene Backbone And Cis-1,4-Pol~yiso~rene Sidechains
A l-gallon "Chemco" reactor is charged with 3 liters
of heptane and 10 grams o~ allyl ether terminated cis-1,4-
pol~isoprene (as prepared in Example 7(g)). The macromolecu-
lar monomer is dissolved 4y stirring and therea~ter the solu-
tion is purged with n~t~ogen for 30 minutes. 10 M1. o~ di-
-ethylaluminum chloride (25% solution in heptane) is added,
followed by the addition of 0.3 gram of TiC13. 139.5 Grams of
propylene is added to obtain a pressure o~ 26 psi. The reac-
tor is heated to 60C., and polymerization is terminated
~ter 18 hours, whereupon the contents o~ the reactor are
slowly poured, with stirring, into a 4-liter beaker containing
C 30 2 lite~s of 1% solution of Ionol antioxidant in isopropanol.
The graft copolymer has higher impact properties than poly-
~r~ ~ nnark -T4-
3763~;
propylene homopolymer~
EXAMPLE ?2
Preparation Of Graft Copolymer Havin~ Pol~yisobut~ene
Bac~bone And Polyst~rene Sidechains
To a solution o~ 20 grams o~ ~o:Lystyrene maçromer
terminated with epichlQrohydrin and having an ave~age molecu-
lar weight of 10,000 ln 1,000 ml. o~ toluene at -70C., there
is added 80 grams o~ isobutylene. 45 Ml~ of boron trichloride
ethyl ether complex is added slowly, the temperature being
maintained at -70C. throughout. Polymerization occurs as
the catalyst is added and is complete almost immediately a~ter
all o~ the catalyst has been added. The resulting graft co-
polymer is obtalned by evaporating away the toluene and wash-
ing the residual solid with methanol.
EXAMPLE 23
PreParation Of Graft Copol~mer Having PolYisobutylene
Backbone And Pol~stYrene Sidechains
To l~000 ml. of methyl chloride at -70C~ there is
added 10 grams of polystyrene macromer terminated with epi-
chlorohydrin, having an average molecular weight of 10~000.To this resulting solution maintained at -70C~, there is
added concurrently and dropwise, a solu~ion o~ 2 grams of
aluminum chloride in 400 ml. o~ methyl chloride and 90 grams
of isobutylene. The time required ~or these additions is one
hour and at the end of this time polymerization is subst~nti-
ally comple~e. The resulting insoluble graft copolymer is
isola~d b~-~Q~r~i~n-o~ t-h~7m~b~1~ne chloride. Similar
results are obtainable by employing either a methallyl or
methacrylyl end group on the polystyrene such as the product
prepared in Examples l(b)9 7(a) and 7(d)~
-75-
~,037~3~;
EXAMPLE, ?4
~a) Preparation Of Pol~styrene Macromolecular Monomer~Capped
With Butadiene And Terminated With Al~yl ChlorideO
2.5 Liters of benzene ~thiophene-free) are charged
into the reactor and heated to 40C. 0. 2 Mlo of diphenyl
ethylene is added as an indicator and the reactor is steril-
ized with dropwise addition of a 12~ solution of sec-butyl
lithium until the persistence of an orange-red color. At this
point, an additional 18 mlO (0.024 mole) o~ sec-butyl lithium
solution (12% in hexane) is added, foll!owed by 416 grams (4.0
moles) of styrene. The temperature of the polymerization mix-
ture is maintained at 40C. for 5 m~n~tes. Then ~he living
polystyrene is capped with butadiene by bubbling butadiene gas
into the reactor until the color o~ the ~olution ch~nges ~rom
dark red to orange. The living polymqr is terminated by treat-
ment with 4.1 ml. ~0.05 mole) of allyl chloride. The macro-
molecular monomer thus prepared is precipitated with meth,anol
and separated by ~iltration. Its number average molecular
weight estimated from gel permeation chromatography is 25,000
~theory: 18JOOO) and molecular weight distributlon i5 very
narrow. The macromolecular monomer produced has the ~ollow-
ing ~tructural formula:
CH3 ~ ~ CH2 -CH = CH--CH2 ~ CH2- CH - CH2
where m equals l or 2.
~b) Prep_ration 0~ Graft CoE~lymer Having A Polvethylene Back-
bone And Polyst~Yrene Sidechains~
2 Grams of butadiene capped, alpha-olefin terminated
polystyrene macromolecular monomer as prepared in Example 18(a)
above, is dissolved in 1500 ml. of cyclohexane and charged
-76-
~37636
.
into a 2-liter ~'Chemco" reactorO T~e reactor is purged with
prepurified nitrogen for 30 minutes, and 22 mlO o~ 25% ethyl-
aluminum sesquichloride solution (in heptane) is addedO The
reactor is pressurized with 21 grams of ethylene to 40 psio
Therea~ter, 0.1 ml. of vanadium oxytrichloride is added and
ethylene pressure is dropped ~rom 40 psi to 1 psi in about 1
minute. The reactor is terminated in 3 minutes by the addi-
tion o~ isopropanolO The polymer is recovered by ~iltrationO
It is known that the physical properties of l:Lnear
high density pol~ethylene are dependent on its extent o~
crystallinity, molecular weight and molecular weight distribu-
tion. It is a balance o~ these characteristicæ that generally
governs the end use properties of ~abricated items. The
gra~t copolymers o~ the present invention, part~çularly those
having a polyethylene backbone and polystyrene sidechains,
modifies the physical properties of polyethylene without a~-
fecting the bene~icial crystalline properties o~ polyethylene.
In order to demonstrate these beneficial properties
of the graft copolymers, as well as the crystalline nature of
the copolymers, several tests were conducted. The ~ollowing
data illustrates the properties of gra~t copolymers having a
polyethylene backbone and polystyrene sidechains prepared by
the procedure described in Examples 9 and 10.
Determination 0~ Macromolecular Monomer
~; .
Content By ID RD SPeCtrOSCOP!Y
Calibration curve of ethylene/polystyrene macro-
molecular monomer copolymerD
C ; Commercial high density polyethylene9 U~SoI~ Micro-
,~ ~ ~
thene ML 708 and Dow polystyrene, Styron~666u are blended in
the ratiosD 80/209 70/30g 60/40, and 5a/50, and extruded
~P `
twice through a Killion extruderD The extruded blends are
-77-
1md~ rk
1~37~3~
pressed into thin films (about one mill) and the infrared
spectrum run on a Beckm~n IoR~ 12 infrared spectrophotometerO
The benzene ring absorbance at 710 cm~l, and the methylene
absorbance at 1480 cm~l are measured and the ratios calculat-
edO The calibration curve is drawn by plotting ab~orbance
ratio vs. % styrene.
Monomer Content Of Copolymers
Ethylene-macromolecular monomer copolymers are
pressed into ~hin films and their IoR~ spectrum obtained on
the Beckman I.R. 12 spectrophotometerO The absorbance at 710
cm 1 for polystyrene-macromolecular monomer is compared to ab-
sorbance at 1480 cm~l, and the macromolecular monomer is de-
termined from the calibration curveO The I.R. spectra is
evidence that a graft copolymer having a polyethylene backbone
and polystyrene sidechains (M~Wo 27,000) having 20~ by weight
incorporation.
Samp~e PreParation And Testing
The copolymers are compression molded into sheets of
about 20 mil thickness for stress-strain testing. The mold is
two 7 inch x 7 inch x 0.040 inch steel plates separated by a
7 inch x 7 inch x 0.020 inch steel shim cut out to make a 5
inch x 5 inch x 0.020 inch center ca~ity. Surfaces are coated
with Dow Corning R-671 Resin as a mold releaseO
Approximately eight grams of polymer are placed in
the mold, and molded at 400F. for 10 minutes at 30 tons
pressure, and cooled down by circulating water~
Three test specimens are cut out of the sheet with a
dumbbell "C" die (ASTM D412-67T) and dimensions are measured
by a micrometer.
Tensile properties are obtained on an Instron Tester
de~ rk - -78-
~3763$
according to ASTM D638 at a cross head speed of 2 inches/min-
uteO
Flexual modulus of the copolymers is obtained on
bars with Instron Tester according to ASTM D790.
Heat de~lection is obtained on bars according to
ASTM D640.
Crystalline Structure 0~ Graft Copolymer Of Polyeth~lene
Backbone And Macromolecular Monomer Sidechains
. _ . ... . .. .
The crystalline nature of copolymers having poly-
ethylene backbones is studied from:
Crystallinity - - X-ray di~fraction3
Melting behavior - - Diffç~ntial Scanning
Calorime~ry;
Crystallite orientatlon - - X-ray dif~ractlon; and
Spherulite ~ormation - - Light mlcroscopy.
Crystallinit~
The measurement of crystallinity by x-ray diffrac-
tion takes many forms but an effective simple method ls to
calculate a crystallinity index (CrI) as follows:
IllO - Iam
CrI a ------ - X 100
IllO
where l11o is the intensity, above background scrattering, of
the llO diffraction peak taken at 21.6 20. Iam is the amor-
phous scattering at 19.8 2~.
For polyethylene, the separation of the x-ray scat-
tering ascribed to the crystalline and amorphous fractLons is
simplified, since the amorphous peak is clearly distinguished
from the crystalline peaks on diffraction patterns. A diffrac-
tometer tracing has been illustrated of a polyethylene with
12% integrally copolymerized alpha-olefin terminated poly-
-79-
1~3~7636
styrene showing the separation of the two ~ractions and the
measurement of peak heights, When .used on published di~rac-
tion patterns of polyethylene, the me~hod gives crystallinity
values in accord with those in which the authors used lnte-
grated intensity measurements ~or the respective crystalline
and amorphous-material.
CrI values o~ several polyethylenes range~ from
72-77. The CrI of polyethylene decreases for copolymers in
proportion to macromolecular monomer content (6-30~o It is
significant, that within experimental error, CrI values are
not lower than those expected by a simple dilution of the
polyethylene crystallinity with an amorphous macromQlecular
monomer.
The diffractometer tracings used for the CrI mea-
surements are also inspected ~or crystal lattice changes and
for di~fractlon line-broadening with macromolecular monomer
addition. Changes in the crystal lattice are not observed,
which means that the macromolecular monomer is not incorpor-
ated into the polyethylene crystal lattice, but rather in
the amorphous regions of the sample... Measured half-widths o~
the 200 diffraction peak shows no decrease in.crystalline size
with macromolecular monomer additionO Thus, di~fractometer
tracings, such as the one wi~h 12% macromolecular copolymer,
and the graph o~ CrI versus macromer content demonstrate a
significant feature of the invention; namely, that the crys-
tallinity o~ the polyethylene fraction is maintained in the
presence of the macromolecular monomerO
Melting Behavior 0~ Macromolecular
Monomer-Polyethylene Copolvmers
A di~erential scanning çalorimeter (DSC) ~s used to
determine the melting behavior of the copolymers and to seek
-80-
~ 03763~
confirmation of the lack o~ ~nterference by macromolecl~lar
monomers with polyethylene crystallitesO A typical endother-
mic DSC trace of a copolymer melting under a programmed ~em~
perature rise has been illustrated. The macromolecular mono-
mer is an alpha-olefin terminated polystyrene having a molecu-
lar weight of 279000. The copolymer has 20% o~ the macromo-
lecular monomer lntegrally copolymerized into the polyethylene
backbon0 polymerO The melting behavi.or of the copolymer
closely matches literature data for unmodified hlgh~density
polyethyleneg even though the sample contains 20~ of the
macromolecular monomer. Undue premelting9 for exampleg does
not occur ln copolymers and the melting point (Tm) is the same
for both 100% polyethylene and copolymer samp~0 Al~o9 on
the basis o~ comparable polyethylene~ made without macromolec-
ular monomers using the same polymerizationg the initlA1 lift-
o~f temperature (89Co )averaged 7C. higher for macromolecular
monomer procedures containing samplesO In one sampleg the
temperature increase is 19 co over the base polyethyleneO
Crystallinity measurements are calculated from heat
of fusion (~H) data obtained from the area under the DSC
traceO The calculations are based on an ~H of 680 4 cal/gO for
100~ crystalline polyethyleneO Al~hough at a differe.nt level9
the crystallinlty values by thls method generally paralleled
those obtained by x rayO
The thermal data on melting and crystallinity thus
confirms the x-ray data that the integrity of the polyethylene
crystallites is maintained ln the copolymer of the present in-
vention. The reverse effect is generally observed, howeverg
in polyethylene copolymers of the prlor art or ln polyethylene
w~th sidechains simply attached to the polyethyleneO Often in
these instances~ crystallinlty not only decreases by more than
~81~
~1~3763~
a simple dilution factorg but also the pol~eth~lene crystal~
lites may show low values for Tm and ~0
'9_
~ ray di~raction patterns were taken o~ s~retched
Instron test samples to determine crystallite orientation and
the ef~ect of macromolecular monomer addition on the ability
of the crystallltes to orien-t,0 The degree of orientation is
determined from the size of the angle sub~kended by the arcs
of the 110 and 200 di~fraction peaks that are shown by ori-
ented ~amplesO Commercial high density polyethylene9 un
stretched and stretched (500%) are shown in Fi'gures VIII~a)
and (b) for comparison with a gra~t copolymer of a pol~e-thyl-
ene backbone having 20~ by we~gh.t incorporation o~ polystyrene
' sidech~in~9 stret.ched, 800~o A stretched homopol~ner ~hG~S a
small 110 arc that subtends an angle o~ 179 whereas the
angle for the copolymer is 48~ even though it is stretched
more than the homopolymerO Henceg the macromolecular monomer
phase acts within the amorphous regions to tie and hold the
crystallite together at high elongations,
In molded ~ilmsg on the other hand9 a somewhat op
posite ef~ect is noted,since copolymers show higher degrees
o~ crystal plane orientation than homopolymersO The ratio o~
the 110 peak over the 200 peak height i.s used in these in~
stancesO When the ratio of peak intensities i3 . in the order
of 30 3g the polyethylene s~mple is consi'dered to have random
orientation. For ~omopolymer polyethylenes9 we prepared and
tested the 110/200 peak ratio varied -from 300 to 4~6. The
orientation ratio ~or copolymers varied ~rom about 3 to as
high as 703 ~or samples mounted .in the dif~ractormeter with
their film surface parallel to the sample holder. Molded
specimens responded in an opposite sense9 howeverg upon subse-
~82
~3763~
quent heatin~ and cooling but without the p~essure used during
molding. Under these circumstances, a copolymer decreased
from 7.3 to 4.8 ~hile the base polyethylene increased from
4.6 to 5.0 in orientation. Similar changes are shbwn in other
samples. These observations on changes in orientation further
illustrate differences in polyethylene properties due to the
presence of macromolecular monomers integrally copolymerized
into the polyethylene backbone.
Spherulite For~ation
.
Spherulitic structures are noted by microscopic exam-
ination in several of the polyethylene or ethylene~macromolec-
ular monomer copolymers prepared. In molded samples, large
(10-30 ~m) spherulites in some of the 100~ polyethylene speci-
mens are observed to decrease in size and in optical perfec-
tion with macromolecular monomer addition. This behavior is
confirmed by crystallization from solvent (Tetrahydronaphthal-
ene) where large and individually separated spherulitic units
can be observed. Polarized light is used and pictures are
taken of spherulites from a homopolymer and copolymers wikh
6, 8 and 20% macromolecular styrene contents. The majority
of the spherulites obtained from the copolymers are smaller
and show more imperfections in structure than those obtained
from the homopolymer. Similar effects are assumed to take
place in samples where spherulitic structures are on the order
of 1.0 to 3.0 ~m in diameter but where it is difficult to
clearly distinguish changes in structure.
To demonstrate that the observed effects are a func-
tion of copolymerization, pictures were taken of crystals from
THN that were obtained from physical blends with 5, 10 and 20%
levels of macromolecular monomer. The spherulitic structures
of the blends were unchanged from the homopolymer.
-83-
~3763~
Thus3 a second feature of graft copol~mers of the
ln~ention is evident in that while the polyethylene crystal-
lites themselves are not lmpaired9 the macromolecular monomer
molecules lnterfere with the aggregation o~ crystallites into
larger morphological units such as spheru:LltesO Their action
fits the pattern of being in the amorphouæ region of the
sample and interferrlng with cr~stallite aggregation but con-
tributing as tie molecu~es to fllm strength and elongationO
The interference wi~h spherulite ~ormation is also
, 10 postulated as contributing towards materia~s with improved
I stress-cracki~g and low temperature flexibility properties.
¦ A number of gra~t co~olymers having polyethylene
backbones and polystyre~a ~idechains are prepared using the
procedure set ~orth in Examples 9 and 10. Also, a number o~
polyeth~lene homopol~mers are prepared in the same manner as
described for the copolymersg except for the omission of the
macromolecular monomer. Chain transfer agents are not used
' to control molecular weight. Products obtained with cont~n-
uous ethylene addition have broad molecular weight distribu-
tions, whereas those obtained by batch polymerizations havenarrow molecular weight distributions.
The graft copolymers and the homopolymers of poly-
ethylene are pressed into filmsg whereby they are each sub-
~ected to tests to determine yield strength~ elongation, ten-
sile ~trength, flex modulus~ and other properties hereinafter
set forth (us ng methods outl~ned aboYe) to demonstrate the
I improved properf.~es of the graft copolymers over the homo-
! polymer of polyethylene. The results of these tests are
I summarized in Tables I III below~
i
1 ~8
:`
~3763~
~ o ~ Lr~
. o . , I
o ~ ~
}~ C~
_
, ~
~o o
C) a)--~ N ~ tr) L~ ~q
O O O I O ~ O o U~
~d ~ O $~
. ~ ~4
j~
C~ . .~
Q -1 o
~; ~ ~ C~ N N ~ ~ c~ Q) tq
~ ~ ~r) N~I N N IIr~ O E I C4
u~ a)b~ ~O ~
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-87-
~03763~:i
The data presented are on unannealed compression
molded samples and therefore illustrate trends o~ physical
propertiesO Optimization o~ physical properties desired re-
quires the synthesis o~ a copolymer with a balance o~ molecu-
lar weightg MWD9 macromolecular monomer content and macro-
molecular monomer molecular weightO
It can be seen ~rom Table I tha-k the physical prop-
erties of polyethylene homopolymers as a ~unction o~ molecular
weight and molecular we~ght distrlbution (MWD) follow the ex-
pected trends~ AlSOg the yield strength does not vary signi-
ficantly wlth either molecular weight or MWDo The elongation
and tensile strength increase with increasing molecular weight,
whereas the modulus9 heat de~lection and melt index decrease
with lncreasing molecular weight, Examples 25 and 26 have a
narrower MWD and show significant increases in elongation and
tensile strength over equival.ent weight average molecular
weight polyethylenes of a broader MWD.
The summation of data for the graft copolymers are
divided into two groups, those having a polydispersity (P.D.)
less than 10 given in Table II and a PoD~ greater than 10
given in Table III in order to establish a logical comparison
o~ the properties as can be seen ~rom the corresponding di~-
ference in properties with polyethylene homopolymers.
By comparing the various properties of the graft
copolymers with the homopolymers of the same average molecular
weight, it is clear that the incorporation of the macromolecu-
lar monomer in the backbone o~ hydrocarbon polymers, such as
polyethylene~ improves many of the properties of polymer sig-
nificantly withQut a sa~rifice o~ beneficial properties pos-
sessed by the homopolymerO Such an improvement in propertiesis not expected in view o~ the ~act that the macromol.ecular
88-
~03763~
monomer is actually copolymerized into the backbone o~ poly-
ethylene and interrupts the polyethylene segmentsO GenerallyJ
such copolymerization with polyethylene results in a loss of
beneficial properties~
It ls also evident ~rom the data shown that the use
of very low molar percent concentrations of the macromolecular
monomer does not alter the crystalline content of polyethylene.
Thus, the spherulitic structure is greatly reduced in the
graft copol.ymers but not affected by simple blends of poly-
1~ ethylene homopolymer with the macromolecular monomer. The
evidence, therefore, indicates that the macromolecular monomer
sidechain seg~ents are in the rubbery amorphous regions o~
polyethylene. In other words, the crystalline portion of poly-
ethylene is the matrix having a rubbery dispersed phase which,
in turn, has a gl.assy dispe.rsed phaseO The high T~ amorphous
polystyrene macromolecular monomer apparently reinforces the
low Tg rubbery phase at low macromolecular monomer contents in
a similar way that the polystyrene domains behave in block
C polymers such as Krato ~
As the content of the macromolecular monomer is in-
creased, the nature of the matrix and dispersed phase of the
amorphous areas of the polyethylene will change until an inver-
sion o~ phases takes place. Now the crystal matrix o~ poly-
ethylene will have a plastic amorphous dispersed phase which,
in turn, will have a rubbery dispersed phase to the extent
that the chain configurations of the amorphous and crystalline
portions of polyethylene will permitO
The ratios of the property value~ set forth in
Tables I - III for polyethylene homopolymers and graft co~
polymers (polyethylene backbone and polystyrene sidechains
having a uniform molecular weight of 15,400) are shown in
~89
~r~ ~ nn~
" ~03763~;
Figures I and II as normalized values vsO the macromolecular
monomer content. These graphs show a definite e~ect of the
macromolecular monomer in increasing all o~ the phys~cal prop-
erties studied over those of polyethylene homopolymers of the
same molecular weight and molecular weight distributionO As
it can be seen in the graph (Figure I) the yield strength
shows a sharp increase in the range o~ 4-12% by weight macro-
molecular monomer content, then a gradual increase with higher
macromolecular content. The elongation and tensile strengths
lQ go through a maximum at about 12% macromolecular monomerO The
~lexural modulus has a sharp increase up to 4% incorporation
of sidechain polymer then plateaus to about 14~-16~ macro-
molecular monomer and again rises but less sharply at higher
concentrations o~ the macromolecular monomer. The heat de-
~lection shows a steady gain with increasing macromolecular
content from 5~ incorporation.
The above data and illustrations demonstrate some of
the advantageous results obtained from gra~t copolymers having
polyethylene backbones and polystyrene sidechains integrally
copolymerized into the polyethylene backbone. Si~ilar bene-
~icial results are obtained using polymerizable hydrocarbon
monomers o~her than ethylene which produce polymers having a
high Tm and a low Tg, e.g., lower alpha-ole~ins such as propyl-
ene, butene-lgpentene-l, etc.
As it is illustrated in Example 24, sidechain poly-
mers having a high Tg, such as polystyrene can be replaced
with low Tg polymers such as polybutadiene and predomi~an~ly
cis-polyisoprene~ For exampleg isoprene can be anionically
polymerized with secondary butyl lithiumg preferably to a
molecular weight of about 15,000 and terminated with allyl
chloride. Alternatively, the rubbery living polymer can be
-9 -
~3*~3~
"capped" with an alkylene ox~de such as ethylene oxide follow-
ed by termination with allyl chlorideg methallyl chloride9 or
methacrylyl chloride to obtain low Tg macromolecular monomers~
The alpha-olefin terminated (allyl chl~ride and anionically
polymerized isoprene) can be used to prep~re super impact poly-
ethylene or polypropylene copolymers util:Lzing known polymer-
ization techniques. For example~ the alpha-olefin terminated
polyisoprene referred to above can be copolymerized with
ethylene using a Ziegler type catalyst system or with propyl
ene using a Natta type catalyst system~
Still another alternative illustrated in the ex-
amples includes the use of hydrocarbon monomers which produce
rubbery polymers in the backbone o~ the copolymer~ Included
among these monomers are isobutylene, butadiene, isoprene9
ethylene-propylene comonomers3 etc~ The physical properties
of the rubbery backbone polymers are enhanced by copolymeriza-
tion or incorporation into the backbone polymer a wide variety
of macromolecular monomers, such as linear polymers anionical-
ly polymerized from s~yrene~ alpha-methylstyrene, ethylene
2Q oxide, ~-vinyl pyridine, methacrylonitrileg NgN-dimethylacryl-
amide, methyl methacrylate, etc. A preferred example being
the macromolecular mono~er of Example 24(a) wherein the poly-
styrene capped with butadiene or ~soprene is terminated with
either allyl chloride or 2-bromomethyl-5-norbornene. The lat-
ter end group is particularly useful in preparing an ethylene-
propylene backbone graft copoly~er ~ollowing the procedure o~
Exam~les 17 and 18.
As it can be seen from the abo~eg the present inven-
tion provides a convenient and economical means for preparing
copolymers utilizing a large variety of hydrocarbon monomers
in forming the backbone polymeric blocks and a wide variety of
-91-
~al376al$
anionically polymerizable monomers in forming the sidechain
polymersO The copolymerization is facilltated by a ~udicious
selection of the terminal end group on the anionically poly
merized polyrnerO Thus, the problem of copolymerizing ~ncom-
patible polymers is solved providing an economical means for
preparing copolymers having a backbone and sidechain polymer
designed to fit one's needs and the particular end product
desired.
EXAMPIE~51
~10 Preparation Of PolystYrene~pol~iso~e-~ene MacP;omolecular
Monomer Terminated With _ lyl Chloride
To a l~gallon Chemco reactorg 2.5 liters of pur~fied
benzene was added, and heated to 40 Co After sterilization
with sec-butyl lithium using diphenyl ethylene as an indica-
; tor, 15.3 ml. (0.019~ mole) of sec-butyl lithium (12~ in hex-ane) was added via hypodermic syringeO 193 G~ of styrene mon-
omer was added in 5 minutes while maintaining the reactor tem-
perature at 40C~ .6 Minutes after styrene monomer was added,
193 g. of isoprene monomer was added in 405 mi~utes. The re-
actor was held at 40Co for 60 minutes, then 204 ml. of allyl
chloride was added to terminate the reactionO The alPha--
olefin terminated polystyrene-polyisoprene macromolecular mon-
omer has a structural formula represented as follows:
wherein n is a value such that the molecular weight of the
polystyrene is about 109000 and m is a value such that the
molecular weight of the polyisoprene segment of the diblock
macromolecular mono~er;is about 10,000.
-92 ~
k
~3763~i
,; ~
To a one~half-gallon Chemco~reactorg 60 gO of the
alPha-ole~in terminated diblock macromolecular monomer (poly~
styrene-polyisoprene te~minated with allyl chl~ride) prepared
in the previous example l~as charged together with lo 5 liters
of dry N-heptaneO The reactor was purged with nitrogen-~or
40 minutes. 30 Mlo of diethyl alumlnum chloride (25~ in N-
heptane) was addedg ~ollowed by 2005 gO o~ titanium trichlo-
ride. The reactor was heated to 75Co, and propylene gas was
introduced to the reactor at the rate o~ 1 liter/minuteO
Polymerization was carried out at 75C,, at 20-25 psi pressure
while ~eeding prupylene at the average rate o~ 005 liter/min-
ute. A~ter 2 hoursg the reaction was terminated by the addi-
tion of ethanolO The resulting copolymer was washed with di-
lute sodium hydroxide solution and dried in a vacuum oven. IR
analysis showed that the diblook macromolecular monomer was
incorporated into the polypropylene backbone. The physical
properties of the copolymer were tested and the results o~ the
te~ts were as follows:
Tensile Strength4970 psi
Yield Strength4720 psi
~ elongation 810%
Flexual Modulus2~05 x 105 psi
Heat Distortion
Temperature144Fo
Izod Impact 1.0 ~to - pound/inch
3o
T~ mQr 1
3~63$
Macromolecular Monomer Term~nated With All,vl Chloride
~ ..
To a l~gallon Chemco~rçactorg 205 liters of dry ben-
zene was added and heated to 40Co After sterilization with
sec-butyl lithium using diphenyl ethylene as a~ indicator,
15.8 ml. ~0.0199 mole) o~ sec~butyl lithium (~2~ in hexane)
was added via hypodermic syringe. 80 Go of styrene monomer
was added while maintaining the reaction temperature at 40C.
1~ Thereafterg 319 g. o~ lsoprene monomer was added and polymer-
ization was carried out at 40Co for 1 hour9 and the living
diblock polymer was terminat2d with 3.0 mlO of allyl chlorideO
The diblock macromolecular monomer had a formula represented
as f~llows-
CH3CH2 - CH ; CH2~ C ~ / H2 ~ CH2 CX ~ CH2
wherein n is a value such that the molecular weight of poly-
styrene is about 49000 and m ls a value such that the molecu-
lar weight of polyisoprene is about 16,000. Analysis o~ the
diblock macromolecular monomer by gel permeati.on chromatography
reveals that the molecular weight distribution of the polymer
is extremely narrow9 i~e.9 the ratio of Mw/Mn is less than
about 1.1.
Preparation ~f~G_aft C~pol~ er Fr m Polystyrene-
Pol ~ opre~_DiO]o~ M~OrO~IG - la~ Mo omer
To a one-half-gallon Chemco~reactor, 300 ml. of the
diblock macromolecular monomer as prepared in Example 52 (40
-94-
~r~ r~
\ ~ ~
g. on dry basis) was charged together with 102 liters of dry
cyclohexane. The reactor was purged with high purity nitrogen
for 50 minutes. 22 Ml. of ethylaluminum sesquichloride solu-
tion (25~ in heptane) was added via hypodermic syringeO
~t~ylene was introduced to the reactor until the pressure
reaohed 44 psi, and the mixture was stirred as rapidly as pos-
sible. 0.2 Ml. o~ vanadium oxytrichloride was injected and
polymerization started imme~lately. During the addition of
the vanadium oxytrichloride, the temperature rose ~rom 25C.
1~ to 60C. As the pressure droppedg ethylene was fed at the
rate o~ 2 liters/minuteO Polymerization was carried out ~or
12 minutes, and terminated by the addition o~ 10 ml. of
ethanol. The polymer was purified by washing wlth cyclohex-
ane, dilute sodium hydroxide solution, and dried in a vacuum
oven, U.V. analysis of the copolymer showed that the copoly-
mer contained 24% of the diblock macromolecular monomer. The
physical properties of the copolymer were tested and the re-
sults of these tests are as follows:
Yield Strength 2500 psi
Tensile Strength 2160 psi
~ Elongation 490~
Flexual Modulus o.6 x 105 psi
Heat Distortion
Temperature 98F.
Iz~d Impact 12.8 ft. - pound/inch
(specimen did not break)
Preparation Of Polyst~rene-Polyiso~rene Diblock
Macromolecular Monomer Terminated With Allyl Ch oride
3 ~ To a l~gallon Chemco~reactor~ 3.0 liters of purified
benzene was added and heated to 40C, After sterilization with
sec-butyl lithium using diphenyl ethylene as an indicator,
-95-
T~Qn1~ ~C
- ~a3763~
4605 mlO ~000585 mole) of sec-butyl lithium (12~ in hexane)
was added via hypodermic syringeO 761 Go of styrene monomer
was added in 15 mlnutes while maintaining the reàction tem-
perature at 40~Co 5 Minutes after completlon of styrene mono-
mer addition9 410 gO of isoprene monomer was added in 4 min-
utesO The reaction was held at 40Co for one hour, then the
reaction was terminated by the addition of 15 mlO of allyl
chloride0 The diblock macromolecular monomer had a structural
formula as described in Examples 50 and 52 hereinabove, where-
in the value of n was such that the molecular weight of poly-
styrene w~s about 13~000 and the value o~ m was such that the
molecular wèight of polyisoprene was 79000O The diblock macro-
molecular monomer was analyzed by gel permeation chroma-tography
and this analysis revealed that the molecular weight distribu-
tion oP the polymer was extremely narrow, iOe.9 the Mw/Mn ratio
was less than about lo 1
EXAM
PreParation Of Graft Copo~mer ~rom PolYs-~rene
Polyisoprene Diblock Macromolecular Monomer
Terminated With A11V1 Chloride a~d Eth~ene
J To a one-half-gallon Chemco~reactor, 200 mlO of the
diblock macromolecular monomer prepared in Example 54 (40 g.
on dry basis) was charged together with 103 liters of cyclo-
hexane. The reactor was purged with high purity nitrogen for
1 hour. 22 Mlo of ethylaluminum sesquichloride solution (25%
ln heptane) was addedO Ethylene was introduced to the reactor
until the pressure reached 44 psio Thereafter9 0~2 mlO of
vanadium oxytrichloride was added and polymerization started
immediately, and the temperature rose from 27Co to 55C. As
the pressure dropped, ethylene was ~ed at the rate of 2
liters/minuteO Polymerization wa$ carried out for 8 minutes,
-96
'rrû dQfn C~ r 1~
~3763~
and terminated by the addition of lO ml. of ethanolO The
polymer was puri~ied by wash~ng with dllu~e sodium hydroxide
solution~ cyclohexane, and dried in a vacuum ovenO UOVo anal~
~sis showed that the copol~mer contained 3815~ of the diblock
macromolecular monomerO The physical prope:rties of the copoly-
mer were tested and the results are as follow~o
Yield Strength 5790 psi
Tensile Strength 5920 psi
~ Elongation 77~
Flexual Modulus lo 6 x 105 psi
Heat D~stortion
Temperature 120Fo
Izod Impact lo 0 ft. - pound/inch
EXAMPLE ~1
Pre~arati.on ~ Diblock
CMacrom~le~u~r Vonome~ "erminated With Allyl Chloride
To a l-gallon Chemco reactor, 2~ 5 liters of purified
benzene was chargedg and heated to 40C~ After sterilization
with sec-butyl lithium using diphenyl ethylene as an indica-
20 tor, 35~1 mlO ~0~044 mole) of sec-butyl lithium (12% in hex-
ane) was added hypodermic syringeO 442 G. of styrene was
added in 13 minutes while maintaining the reactor temperature
at 40C. Ten minutes a~ter styrene monomer was added, 8804 gO
of isoprene monomer was added in 4 minutes. The reactor was
held at 40Co for 30 minutes, then 3O6 mlO of allyl chloride
was added to term~nate the reactionO The recovered diblock
macromolecular monomer had the same structural formula as rep-
resented in Examples 50 and 52 hereinabove9 with the exception
that the value of n was such that polystyrene had a molecular
30 weight of about lO~000 and the value o~ m was such that the
molecular weight of polyisoprene was about 2,0000 The polymer
~c,do. ~ k 97
1l~37/~3~
was analyzed by gel permeation chromatography and the anal~sis
revealed that the molecular weight distribution o~ the polymer
was very narrow~ iOe~9 the Mw/Mn ratio was less than about 1.1,
PreParation Of Gra~t Copol~mer
Pol~isoPrene Diblock Macromolecular Monomer Terminated
~ L~LI_ __ ___nd A
To a onerhal~-gallon Chemco~reactor, 155 g. o~ 19~3%
lQ by weight of the diblock macromolecular monomer prepared in Ex-
ample 56 solution (30 gO on dry basis) was charged together
with 106 liters o~ puri~ied cyclohexaneD 22 Ml. of ethylalu
minum sesquichloride solut,ion ~25~ in heptane) was added via
hypodermic syringe. Then 19 liters (35 g.) o~ prop~lene gas
was introduced into the reactor. As soon as 0.2 ml. o~ vana-
dium oxytrichloride was in~ected, polymerization was started
by continuous ~eed of ethyleneO Ethylene was addéd to the re-
actor at the rate o~ 2 liters/minute for 14 minutes (35 g.).
Polymerization was carried out for 24 minutes, and terminated
by the addition of isopropyl alcohol.
The copolymer solution was placed in a stainless
steel beaker and 1 liter of dilute sodium hydroxlde solution
C ~ and 1 g. of Irganox 1010 antioxidant was added. The mixture
was stirred by Arde-Barinco Mixer to remove catalyst residue
from the polymer The copolymer was coagulated and dried9 and
evaluated as (1) thermoplastic elastomer, ~2) alloying agent
~or blending commercial EPDM and polyisoprene ~or developing
high impact plastics, (3) EP rubber which can be cured with
conventional diene-based rubber to improve compatibility and
3Q ozone resistance,
T~ad~rn Q ~ ~ -98-
376;~
Ox~de ~nd
~ lb~ sY~ _Chloride
A sta*nless steel reactor was charged with 1950 22 kgo
o~ puri~ied benzeneO The reactor was hea-ted to 40Cg and the
solvent and reactor were sterilized with sec-butyl lithium us-
ing diphenyl ethylene as an indicator. Following steriliza-
tion~ 126058 g, (lo 9764 moles) of sec-butyl lithium ~12% in
hexane) w~s added to the sterilized solventg ~ollowed by the
addition o~ 19.47 kg~ of styrene over a period of 30;45 min~
utesJ while maintaining the reactor temperature at 36-42C.
Following the additlon of the styrene, 48~62 kgo o~ isoprene
wa~ ~dded to the reactor ~ollowed by the addition o~ o.38 kg.
of ethylene oxide to "cap" the diblock living polymerO The
"capped" diblock polymer was terminated by the addition o~
0.22 kg. of methacrylyl chloride to obtain the methacrylic
aci~ ester,represented by the formula~
Q
CH3CH2--CH_ ~CH2 ~ H~ CH ~ CH2 -~H2cH2-o-c~c = CH2
CH3 ~ ~ ~ ,n / C ~ C CH3
wherein n is a value such that the molecular weight o~ poly-
styrene is about 10~000 and m is a value such that the molecu-
lar weight o~ polyisoprene is about 25gO00~ Analysis o~ the
diblock macromolecular monomer by gel permeation chromatography
reveals that the molecular weight distribution of the polymer
is extremely narrow9 i.e,g the ratio o~ Mw/Mn is less than
about 1.1. Following recovery o~ the macromolecular monomer9
68 g. of Agerlite Superlite (~nti-oxidant) wa~ added to the
polymer to stabilize it against premature oxidationO
_99_
~r~de~rk
103763~
The procedure o~ Example 59 w~ repeated using in
pl~ce of methacrylyl chlorlde, an equivalent amount o~ maleic
anh,ydrlde to produce the maleic half ester o~ the polystyrene~
polyisoprene diblock macromolecu~ar monomer having the ~ormula:
CH3CH2--CH ~ CH2 CH ~ ~C ~ ~CH2- , 2 ~ \
3 L ~ / C = C jCH
n ICH3 H m CH
~IOC
o
wherein n and m are positive inte~ers as hereinabove de~ined.
The hereinabove maleic hal~ ester terminated macromolecular
monomer was copolymerized with vinyl chloride (10 parts by
weight o~ the macromolecular monomer with 90 parts by weight
o~ vinyl chloride and a chain trans~er agent) to produce a
chemically ~oined, phase separated gra~t copolymer possessing
superior properties with respect to processability and
strength. The gra~t copolymer was blended with polystyrene
(DOW 666) to impart excellent properties.
20 ` EXAMPLE 60
Preparation Of Gra~t Copol~mer From Methacr,ylate Ester Poly-
st~rene-Poly1,saprene Diblock Macromolecular Mono~r~i~Lo_lL~lL~
A suspension copolymerization using the methacrylate
ester terminated polystyrene-polyisoprene diblock macromolecu-
lar monomer prepared in Example 59 was conducted by the pro-
cedure described below. An aqueous solution and a monomer
solution were both ~reshly prepared b~ore use~ The ingredi-
ents of the aqueous stabillzer solution and monomer solution
were as ~ollows:
-100 -
~103763~i `
Aqueous
; Distilled Water 375 g~
Polyvinyl~pyrrolidone 0.625 g.
(Luviskol K-90)
. ..~,
Monomer Solution
Methacrylate terminated
macr~molecular monQmer
(Example 59) 291 g. (2509% solids
solution in
benzene, 7504 g.)
S-tyrene 177 g-
Benzene (solvent) 52 g~
AIB~ ~ lo 33 g.
(poiymerization initia~or)
The aqueous stabillzer solution was charged to a
rinsed quart bottle, and the bo~tlç was capped with a butyl
rubber gasketed cap having a Mylar~ ilm lining. ~he bottle
was purged with nltrogen via syrlnge need~e be~ore in$~oducing
the monomer solution. The mo~o~er solution was then ~hargçd
to the bottle with a hypodermic syringe, and the bQtt1e was
placed in a bott~e polymerizat~on ~th and rotated at 30 rpm
at 65C~ ~or 20 hours. The ~uspensio~ was then cooled, fil-
tered, washed with water, air dried, and screened at ambient
temperature, 117 G. of the copolymer was recovered, repre-
sentin~ a 95~ conversion o~ styr~ne.
The chemically ~o~ned, phase separated gra~t copoly-
mer was compressio~ molded tq a clear plastic and ~ad the fol-
lowing physical properties:
Flexual Modulus 190,000 psi
(13,360 kg./cm3)
Heat ~istortion
Temperature 170QF~ (77C.)
Izod Impact Strength 1.1 fto/ ound inch - 9.5
ft. ~pound inch
As it can ~e seen ~rom the above data, the copolymer
r~a~m~r k -lo~
37636
had remarkable physical properties and had the added advantage
of being a çlear plastic.
EXAMPLE 61
PreParation Of Graft Copol,ymer ~rom Pol.Yst~rene Terminated
With Vin,yl-2-Chloroeth!yl Ether ~nd Eth.~l Acr,vlate
To a solution of 18 grams of octylphenoxy polyethoxy
ethanol (emulsifier) in 300 grams of deionized water there is
added, with vigorous agitation in a Waring Blender, a solution
of 30 grams of the polystyrene product of Example 1 and 70
grams o~ ethyl acrylate~ The resulting dispersion is purged
with nitrogen, then heated with stirring at 65C.~ whereupon
0.1 gram of ammonium persulfate is added to initiate polymer-
ization. Thereupon, 200 grams of ethyl acrylate and 0.5 gram
o~ 2~ aqueous ammonium persul~ate solution ar.e.added p~rtion-
wise over a period o~ three hours, the temperature being main-
tained through~ut at 6~C. The resulting graft copolymer
emulsion is cast on a glass plate and allowed to dry in air at
room temperature to a ~lexible self-supporting filmO The film
is shown to contain polystyrene segments by extraction with
cyclohexane which dissolves polystyrene; the cyclohexane ex-
tract on evaporation yields no residue.
EXAMPLE 62
Preparation~;Of...~ t CoPo-l.ymer Of Poly~alpha-methvlstYrene?
Terminated ~ith VinYl Chloroacetate And Butyl Acrvlate
A solution o~ 50 grams of poly(alpha-methylstyrene)
macromer terminated with vinyl chloroacetate and having an
average molecular weight of 12,600 and 450 grams of butyl
acrylate in 1,000 grams of toluene is purged with nitrogen
at 70C., then treated with 1 gr~m of azobisisobutyronitrileD
The temperature is maintained at 70q CD for 24 hours to yield
a solution of graft copolymer which is cast as a film on a
-102-
~qdQ ~r~
1~3763 .~;.?
glass plateO The dri.ed film is sli.ghtly tacky and is shown to
contain polystyrene ~egments by extraction with cyclohexane
and evaporation of the cyclohexane extract, as aboveO
EXAMPLE 6~
Preparation 0~ Graft Copol~mer Of P~lystyrene Macromer
Terminated With Methacr~LYl Chloride And Eth~l Acr~ _ e
A mixture o~ 21 grams of polystyrene macromer termin~
ated with methacrylyl chloride and having an average molecular
weight of 10,000 prepared as in Example 6, 28 grams of ethyl
acrylate and 0 035 gram o~ azobisisobutyronitrile is prepared
at room temperature and kept ~or 18 hoursl under nitrogen, at
67C. The resulting product is a tough, opalescent material
whlch can be molded at 160C. to g~ve a clear, tough, trans-
parent sheetO
EXAMPLE 64
HomopQlymerization Of Met acr~late Terminated Polystyrene
The methacrylate terminated polystyrene bf Example 8
is sub~ected to homopolymerization conditions by suspension
polymerization as followsO
Aqueous Solutiono
5% Lemol~42-8~8 (Polyvinyl alcohol) 3.0 g.
Distilled water 300.Q g.
Monomer Solution-
Methacrylate terminated polystyrene 20.0 g.
Lauroyl peroxide 0.16 g.
Benzene (thiophene-free) 30.0 g.
The aqueous polyvinyl alcohol solution is charged
into a clean quart bottle and sparged with nitrogen for 15
minutes. The methacrylate terminated polystyrene macromolecu-
lar monomer solution is added to the bottle, and the bottle iscapped after flushing with nitrogen for 2 mi~utesO The bottle
is placed in a 70Co bottle pol~merization bath for 17 hours.
~de~ k -103~
~037636
The product is filtered, dried, and dissolved in
tetrahydrofuran (THF) for Gel Permeation Chrom~tograph (GPC)
analysis. No gel is found in the THF solution~ In the GPC
chromatogram, the ratio of the area of the unreacted macro-
molecular monomer peak at 32 counts to the total peak area
showed that 75.9% of the macromolecular monomer remained un-
reac~ed. The analysis of the GPC, theref3re9 reveals that
only 24% of the macromolecular monomer reacted, and this con-
version resulted only in a low molecular weight polymer.
EXAMPLE 65
Polymerization Of Acr,ylates In The Presence Of Po}Yst~rene
This example illustrates that a polystyrene does not
graft to an acrylate backbone at the polystyrene segment, es-
tablishing that the macromolecular monomers of the invention
copolymerize with acrylates and other polymerizable monomers
through the terminal dDuble bond.
The attempted polymerization was conducted in a
stirred 3-neck flask fitted with a condenser by the following
recipe and procedure:
Po~ymerization Recipe~
Polystyrenel 18.0 g.
r' ~ Ethyl acrylate (R & H No. 3871) 42.0 g.
~o AIBN (VAZ0)~ 0.158 g.
Benzene (thiophene-free) 120.0 g.
DMS0 (reagent grade) 12000 g.
lLiving polystyrene having a molecular weight of
- about 10,000 terminated with methanol.
The materials are charged into the flask and the
clear solution is heated under a slow flow of nitrogen ~or 13
hours at room temperature of 61Co to 80C. After completion~
the polymer solution has a total solids content of 190 6
(theoreticalO 20.0%).
The product mixture is precipitated and dissolved in
-104-
Trqde~n~ r k
~3763!~i
THF for GPC analysis. The unreacted polystyrene i8 determined
~rom the area of the polystyrene peak in the GPC chromatogram
of a known sample weight in~ected, and using the polystyrene
peak area/gram calibration from polystyrene standards shown in
the ~ollowing Table.
CPC Determin_tion Of Unreacted P~ st,Yrene
,
Unreacted
Polystyrene Unreacted
~t. Product Polystyrene In In~ected Polystyrene
10 In~ected Peak In
(Grams) Area(Grams) ~ Product
o.oo8039 0.1778 0.00268 33.3
(a)Calculated ~rom standard 66.5 g. area/l.000 g.
macromolecular monomer.
The above determinat~on shows that the polymer prod-
uct cont&ined 33.3~ unreacted polystyrene. There~ore9 little
or no grafting of ethyl acrylate to polystyrene macromolecular
monomer occurred during the polymerization.
Pre~aration Of Graft Co~gl,rmer Havi~ng'Pol,Yst,rrene
Sidechains And Poly(butrl acrrlate) Backbone
The following ingredients are charged into a quart
bottle which had been washed, dried, capped and flushed with
nitro,gen.
Methacrylate terminated polystyrene
~prepared by procedure of Example 8,
except that ~n = 11,000) 15.0 g.
Ut~l acr,rlate (Rohm & Haas 3480) 45.0 g.
AIBN~(VAZ0) ~ Oo09 g.
DMS0 (reagent grade) 195.0 gO
Benzene (thiophene free) 19500 gO
The methacrylate terminated polystyrene ls first
dissolved in the benzene/DMSO solution9 followed by dissolving '
the butyl acrylate and V~Z0 in the solutionO The homogeneous
-105-
~r~dQr~a, k
~03763~
solution is introduced i~to the nitrogen filled bottle via
syringe. The bottle ls placed in a 67Co bot~le polymeriza-
tion bath and rotated at 30 rpm. Samples are removed by
syringe and sh~rb stopped wi~h 10~ ME~Q at 75 minutes, 120
minutes and 210 minutes. At 300 minutes polymerization time,
the remainder o~ the bottle is short stopped with 4 drops 10
MEHQ in ethanol.
The butyl acrylate conversions are obtained by total
solids determination on portions o~ the samplesO The remain-
der of the samples are precipitated in methanol, dried, anddissolved in T~ifor GPC analy$is. The methacrylate termin-
ated polystyrene has a peak at 31 counts on the GPC chromato-
gram. The GPC chromatograms of products of 75, 1209 210 and
300 minutes Rhows the disappearance of the peak at 31 counts.
Analys's o~ the GPC çhromatogram revealed that 25~6~ of the
graft copolymer is polystyrene and 74.4% is poly(butyl acry-
late)0
The above procedure is repeated several times using
the same methacryla~e tçrminated polystYrene having a malecu-
lar weight of 11,000 and a Mw/Mn of less than about 1.1, bycopolymerizing increased amounts of butyl acrylate~ replacin~
butyl acrylate wlth ebhyl acrylate andlmebhyl methacrylate.
Table 4 below summarizes the res~lts of these copolymeriza-
tions.
-106_
1037636
~AB~E 4
C_mpositions 0~ Methacrylate Terminated Pol~styrene-
Acr,ylic Copolymers Prepared i~ DM;S ~ e~nzene Solution
% Macro-(a) Copolymer
molecular Macro Com-
Monomer Polyme~- molecular position
in ization Comonomer Manomer (~ Macro-
Monomer Time, Conver- Conver- molecular
ComonomerFeed Hours si~n % _sion ~ Monomer~
BA 25 2, 36.2 37^3 2506
3.5 62.3 65.7 26.0
' 5 75.6 85.5 2704
BA 50 2 13.5 18.4 57.7
4.75 ~7.0 7700 53.5
EA 25 2 23.2 30~1 30.2
3.5 58.3 67.2 2708
77.6 90.4 28.0
EA 50 4.75 69.o 80.7 53-9
MMA 25 2 15.5 10.~ 18J2
~8.3 530~ 26~9
MMA 50 2 12.0 22.9 6506
4.75 35.7 32.0 47.3
(~)SllMA = Methacrylate termin~ted polystyrene~ 11,000 ~n
- ~ethacrglate terminal group
EA = Ethyl Acrylate
BA = Butyl Acrylatq
MMA ~ Methyl Methacrylate
XAMPIE~r 6,7
Prepartion 0~ Gra~t Co~olym~er,Havln~ Pol,vstyrene
Sidechains And PolY(meth,Yl methacr,ylate) Backbone
The ~ollowing ingredients are charged into a clear
quart bottle, capped, purged with nitrogen, and polymerized
for 17~ hours in a 7~$~ bottle polymerization bathO
107-
~37~3~i
Methacrylate termin~ted polystyrene
~product o~ Example ~) 2705 gO
Methyl methacrylate llOo O go
Benzene (thiophene-~ree) 41300 g~
; C AIBN~(VAZ0 64) lolO g~
t-Dodecyl mercapt~n 0070 mlO
The resulting graf~ copolymer is recovered by pre~
cipitation of part of the copolymer in methanol and the other
part in cyclohexane to give a combined yield of 87~9 Glear,
brittle films are obtained from the cyclohexane - or methanol -
precipitated products, The methaGrylate terminated polysty
rene alone has a peak at 32 counts on the chromatogram of the
GPC. Howeverg a GPC chromatogram on the unworked-up product
o~ the gra~t copolymer illustrates that no unreacted methacry-
late macromolecular monomer is detectable at 32 countsO There-
~ore, it m~st be assumed that all of the methacrylate termin-
ated polystyrene copolymerized with the methyl methacrylateO
EXAMP~E 68
.
Preparation Of Graft Copolymer Havi ~Pol~styrene Sidechains
And PolY(butyl acrylate) Backbone BIY Suspension Copolymeriza-
tion
By emplaying the same methacrylate terminated poly-
styrene used ~n Example 66 ~i.e., M.W. = 11~00 and Mw~Mn
less than about lo 1~ prepared by the procedure of Example 8),
the following ingredients are charged into a clean~ capped3
~nitrogen purged quart bottle:
Distilled water 150~0 gO
Lemol~42-88 (5% solution of
polyvinyl alcohol) 3~0 gO
Disodium phasphate o.80 g.
Monosodium phosphate OOQ5 g~
Therea~ter, the following solution is introduced into the
bottle via syringe-
~r~d~rn~ ~ k -108-
~l)3763$
Methacrylate terminated polystyrene 2000 gO
But~l acrylate 30~0 gO
Lauroyl peroxide 0uI gO
The bottle is rotated for 16 hours, at 65Co 9 ~ol-
lowed bv heating ~or 2-3 hours at 86Co I'he product beads are
washed with water, filtered and driedO The molded film i~
clearg rubberyg and strong. The transparency of the film ~n-
dicates that little unreacted methacrylate terminated poly-
styrene is presentO
Unlike copolymerization in DMS0/benzene solution,
the reactivity of methacrylate terminated polystyrene ~ith
acrylic monomers in suspension polymeri.zation is that predlct-
ed ~rom llterature reacti~ity ratios. It is seen l~ Table 3
below that the polymerizable macromolecular monomer has a
greater relative reactivity than the butyl acrylate monomerO
The relative reactivity ratio~ r2, o~ the methacrylate ter-
minated polystyrene (Ml) with butyl acrylate (M2) is about 004
(Ta~le 5). This corresponds with the literature value o~ 00 37
~or methyl methacrylate/butyl acrylate.
TABLE~
Composition Of Methacr~late Terminated Polyst!yrene-But~
Acr,vlate Copolymers Prepared By Suspension Polvmerization
-r2-
Copolymer version
% Macro- Macro- Com- % Macro-
molecular Pol~ymeri- ~utyl molecular position molecular
Monomer zation Acrylate Monomer (% ~acro- Monomer
In Monomer Time, Conver- Conver- molecular Con-
30 Feed Minutes sion ~ sion~ Monomer) versflon
. . _ _ . .. . _
2902 4700 4105 o.6
135 6004 7906 35~6
180 6809 8109 33~1
700 15~ 5 68~ 9 0.1~5
lOo 1 26~ 3 710 g 0~ 38
135 67~ 4 8100 5406
180 7900 85~ 6 5200
~109 -
~L~3763$
.V Suspension Co-
polymerization
A suspension copolymerizatio~ using a methacrylate
terminated polystyrene prepared by the procedure of Example 8
having a molecular weight of about 16,000 and a Mw/Mn of less
than about 1.1 is Gonducted by the procedure described below.
An aqueous ~olution and a monomer solution were both freshly
prepared before useO The ingredients of the aqueous stabil-
izer solution and monomer solution are as followsO
Aqueous_St bilizer_Solution:
Distilled water 30000 gO
5~ Lemo ~2-88 poly~lnyl
alcohol solution ~Borde~)3.0 gO
Disodium phosphate 106 gO
Methacrylate terminated poly-
styrene 3. g-
Ethyl acrylate (Rohm ~ H~as)35.0 g,
Butyl acrylate (Rohm & Haas)35.0 g.
Benzene (thiophene-free)14.0 g~
Lauroyl peroxide oOo84 gO
The 5% polyvinyl alcohol solution is prepared by
dissolving Lemol~42~88 in distilled water. The aqueous sta-
bilizer solution is charged to a rinsed quart bottle, and the
bottle is capped with a butyl rubber gasketed cap having a
Mylar film liningO The bottle is purged with nitrogen via
syringe needle before introducing the monomer solutionO
The monomer solution is then charged to the bottle
with a hypodermic syringeg and the bottle is placed in a bottle
polymerization bath and rotated at 30 rpm at 55Co for 16
-110 -
~tr~dem~rk
~(~3763i
hours. The polymerization reaction is completed using the
follow~ng temperature cycle. The bath temperature is raised
to 65C. for 3 hoursg 80C~ for one hour and 4 hours at 92-
95C. The suspension is then cooled9 ~ilteredy washed with
water and dried at ambient temperatureO
The beads are milled for 2 minutes at 145Co roll
temperature for analysis and physical testing, The yield is
~1~6~ of theoretical ~there is some loss of material during
milling). The amount o~ unreacted methacrylate terminated
polystyrene in the product is 303~.
The samples are prepared for physical testing by
briefly milling the dried polymer beads prior to molding spec-
imens in order to eliminate insoluble gelO The milled prod-
ucts are dissolved in THF for GPC determination ~or unreacted
methacrylate terminated polystyrene. The molded specimens
which had not undergone shearing by milling did not generally
develop optimum physical properties. All products for analy-
sis are milled 2 minutes on a lab mill with a tight nip and
145C. roll temperature. Specimens ~or tensile ~esting are
compression molded for 10 minutes at 170Co and 1100 psio
Only contact pressure is applied until the platens reach the
required temperature, then full pressure is applied to the
mold. Pressure is maintained while cooling the mold to pre-
vent the formation of bubbles.
The molded sheets (19 mils) of the 30~ incorporated
methacrylate terminated polystyrene copolymer of this example
are tough and transparent and the properties are described in
Table 6 below.
711~3~
TABLE 6
~perties 0~_~0~ Methacrylate Termi
Unreacted macromolecular monomer (~) 3.3
THF-insoluble.gel content of milled and molded .
sample, % o~4
Tg of acrylic elastomer component by DSC9 C. : -37
Water absorptiong 24 hours9 % approximately 0.3
Yleld strength3 psi (a) 360
lO Tensile $trength, psi (a) 1630
Ultimate elongationg % ~a) 1~75
Tensile set (% increase of original length) ~a) 35
(a)Tensile testing was conducted on Instron at lO inches/min-
ute crosshead rateO
Pre~aration O~ Gra~t Copol2~e Havin~_Polyst~rene Sidechains
And Poly(!but~l acr~late)_Backbone B~Suspension Copol~meriza-
tion
A 2-liter glass resin kettle (5 inch diameter)
emersed in a temperature controlled water bath is charged with
600 grams o~ an aqueous stabilizer solution containing 600
grams of distilled water, 300 grams of 5% Lemol 42-88 poly-
vinyl alcohol solution (Borden), and 3020 grams o~ disodium
phosphate. The reactor is equipped with a condenser, thermom-
eterg nitrogen inlet, and a stirrer with a 4-3/8 lnch crescent
shaped l-piece Teflon paddleO While heating up the aqueous
solution, the reactor is purged with nitrogen at 100-200
mlO/min. ~or 50 minutes, The nitrogen flow.is-reduced~ and
225.2 grams of a monomer solution is charged to the reactorO
The monomer solution consists o~ 6000 gram~ o~ a methacrylate
terminated polystyrene prepared by the procedure o~ Example 8
and having a molecular weight of about ll,000 and 140.0 grams
of butyl acrylate, 2800 grams of benzene (thiophene~free)g and
0.280 gram of lauroyl peroxi.de (Alperox, Lucido)~ The stirrer
is adjusted so the blade is lo 5 inches below the surface, and
rk -112-
~37~3~i
stirring i6 started at 300 rpm, then reduced to 230 rpm.
(Monomer pooling is observed at slower stirrlng speedsO) The
bath temperature is maintained at 62Co with an internal tem-
perature of 60-61C, After 12 hours, monomer droplets are ob-
served as bein~ converted into be~ds. The internal tempera-
ture is raised t~ 90C. after 5~ hours, and the polymerization
is finished in another 1~ hours, The produc~ is filtered
through ~ 6a-mesh screen, washed with distilled water and al-
lowed to dry at room temperatureO The ~eight o~ the dried
polymer beads (5-12 mm. lengthJ 3-4 mm. diameter) is 19007
grams. After milling (2 minutes at 145Co ) then molding of
the product ~or 10 minutes at 170C.~ a transparent ela~tomer
is obtained~
Table 7 below illustrates the physical propqrtles
obtained by çopolymerizing the macromolecular mono~ers of the
present invention prepared by suspension polym~rization by the
procedure in the examples above.
-113-
103763~
TA~LE 7
Physical Properties Of Macromolecular
.~
Monomer/~crylic Co~olYmers(a)
Macro-( ) (b)
molecular Elon_ Pçrma- ~mmedl-
Monomer Yield Tensile ga- nent ate
Type 5trength Strength tion Set Recovexy
Wt. % Comonomer (PSi~ ~Si~_ (%) ~.
SllMA 20 1 ol EA oBA ~ 820800 0-2 9805
10SllMA 25 1 1 ~AoBA 130 1420 790 5 95
SllMA 30 1 ol EA oBA 380 1500810 4 87
SllMA 35 1 1 EA:BA 560 1930 56050 77
S16MA 25 lal EAaBA - 1310 73010 96.8
S16MA 25 2:1 EABA ~ 1800 70023 91
S16MA 30 1:1 EA:BA 270 1660 55022 91
S16MA 40 1:1 EAaBA1220 2170 l~oo108
S16MA 45 1~1 EA:BA1760 2490 350128
SllMA 45 EA 2090 2400 290140
S16MA 53 BA 2540 2030 276105
20S16MA 50 1:1 EA:BA2680 2950 240125
(a) Specimens 18-19 mills thickne~$ pulled on Instron at
10 inches/minute.
(b) % Recovery = ~ Elongation - % Set/~ Elongatio ~ x 100
(c) SllMA - Polystyrene, 11~000 molecular weight, metha-
cr,~late terminal group.
S16MA = Polystyrene, 16,000 molecular weight metha-
crylate terminal ~,roup.
The examples (Examples 66 ~ 67) above illustrate
thab the polymerizable macromolecular monomer of the present
invention copolymerizes and is incorporated into the backbone
polymer at a uniform rate that does not change with conver-
sion (Table 4). This data (Table 4) illustrate that the ini-
tial composition of the copolymer is the same as the initial
charge ratio (r2 = 1). The rea$ons for this behavior of the
methacrylate terminated macromolecular monomer is not under-
stood3 but the effect is reproducable~ The results of these
-114~
~Qa7~i3~i
experiments indicate that with very large monomers9 eOgOg the
macromolecular monomers in very low molar concentra~ ons9 a
Po~sson distributl~n of segments can be achievedO This dls~
tribution permits the synthesis o~ predictable9 uniform graft
polymer structure~O It is shown in Table 3 that the r values
correspond to the literature r values in this type of copoly-
merizatlonO
It can be seen from the table that at low macromo~
lecular monomer levels (20~30%) the products are thermoplastic
elastomers with good recovery. At 30-45% macromolecular mono
mer contents9 the products are ~lexible thermoplastics with
increasing tensile strength and yield strength, and decreasing
elong~tion and recovery, as the macromolecular monomer Content
increasesO
As it would be expected, the macromolecular monomer/
~crylate copolymers have many potential uses as thermoplastic
elastomers~ For example, emersion of a macromolecular mono
mer/EA/BA terpolymer in machine oil ~or 5 days at room temper-
ature produces a weight increase o~ only 0.9~. The s~rength
and recovery of the specimen appears to be une~fected by the
emersion in oilO The estimated use temperature range of this
thermoplastic elastomer is about -30C. to +50Co Oil resist-
ance and brittle temperatures can be modified by comonomer
composition used in the macromolecular monomer copolymeriza
tionsO The use of macromolecular monomers with higher glass
transi.tion temperatures than polystyrene will produce a signi-
ficant increase in the upper temperature limits o~ these prod-
uct~.
These products have been found to be useful in nu-
merous applications such as gaskets, O-rings, sealants9 adhe-
sives9 etc.g in contact with hydrocarbon solvents and oils,
-115-
~376~`6~
water9 glycolsg etc. The capabi.lity of being injection molded,and the lack of e~tractable curing ingredients are among the
advantages offered by the novel macromolecular monomer gra:ft
copolymers of: the inventionO
And Poly~but~l a_r~l.ate) Backbone Prepared By Latex Copolymer~
izatiorl
Stabl.e ~atexes are prepared by copolymerization of a
10 methacrylate terminated polystyrene macromolecular monomer
prepared by the procedure of Example 8 and having a molecular
welght of about; 139000 with acrylic monomers is accomplished
by the :~ollow.~ng recipe and procedureO
Solution A~
Distilled water (boiledJ nitrag~n purged) 4760 0 gO
Sodium bicarbonate solution (570~ 160 0 gO
rD Igepa~Co-880 solution (10% aqueous
~d solution, GAF) 80Jo gO
SolutiorI B.
Butyl acrylate 28000 gO
Methacrylate te~ninated pol:Ystyrene
(M~Wo = 139 000,~ ~w/~n 1.1)120.0 g.
- Toluene ~ 40 g.
Ninate~01 (60~ active, Stepan,
calcium dodecylbenzene sulfonate) 130 6 g.
t-Dodecyl mercaptan 0.20 mlO
Solution C~
~ ~ .
Lauroyl peroxide solution
( 1. 6 go in 2000 g., toluene)2106 g.
The molecular weights of the copolymer products can
be increased by elimination of mercaptan in the recipe.
The emulsion is prepared in a 105 liter S~ beaker.,
cooled in an ice bath and made with a Ty~e CS 4AMP 8,ooo rpm
Black and Decker homogenizerO Solution A is placed in the
beaker and a nitrogen purge ls startedO The homogenizer is
started and Solution B is introduced in one minute and stirred
~116
' \ r~nQr ~
- ~37~ii3~i;
~or an additional lO minu~esO Solution C is therea~ter added
and the entire contents stirred for an additional 2 minutesO
The above emul.sion is charged ~nto a 2-liter glass
resin kettle fitted with ~our baffles slx inches by ~ inch and
stirred with a 3 inch diameter six blade turbine agitatorO
~itrogen purge and stirring (500 rpm) are started while the
temperature is raised to and held at 67Co After 5 minutes
at 500 rpm~ the speed o~ the agitator is reduced and held at
175 rpmO After l9 hours at this temperature, the reactor con-
tents are cooled to room temperatureO The latex is ~iltered
through clothO The resulting polymer has a total solids con-
tent of 3902% and a Brook~ield viscosity at 25 (LVI 60 rpm)
0~ llo9 CPSJ a parti.cle s:Lze o~ 2 microns, a pH o~ 7.6 and a
~reeze-thaw stability o~ 2 cyclesO Analysis reveals that only
lo 5% 0~ the methacrylate terminated polystyrene remained un
reactedO
ExAMpLE, 7?
Preparation Of Graft Copol~mer Havin~Polystyrene Sidechains
And Pol!Y(but~l acr,vlate)/Pol,y(eth.vl acr.~late) Co~ol2~eric
Backbone B~ Latex CoPol~m-erization
A l.atex copolymerization employing the same procedure
as described in Example 71 above is employed with re~pect to
the following recipeO
Solution A:
Distilled'water (boiled~ nitrogen purged) 401050go .
Sodium bicarbonate (5% solution) 17.6 g.
Igepal'~C0-880 solution (10% aqueous
solutiong GAF) 7700 g.
-rr~ ~It n~ r )C
~117
Solution B: ~7636
Ethyl acrylate 15400 gO
N-butyl acrylate 15400 gO
Methacrylate terminated polystyrene
~MoWo = 13,000) 132-o gO
~r~ Xylene 4400 gO
~inat ~ 01 (60~ active, ste~
calcium dodecylbenzene sulfonate) 120 9 go
t-Dodecyl mercaptan 0007 mlO
Solutio, ~ ,:
Lauroyl peroxide solution (009 grams ln
2200 grams xylene) 2209 g~
As pointed above, the emulsion is prepared in the
same manner as described in Example 71, however, the polymer-
ization is run at 55aC. for ~ hours and ~inished at 95Co ~or
2 hours. The solids content o~ the butyl acrylate/ethyl
acrylate/macromolecular monomer polymer latex is 43.6% and has
a part~cle size of` 3-4 microns and a pH of 7.5. There is ho
coagulum in the latex polymer~ ~ust as there was none in the
polymer prepared in Example 710
The gra~t copolymers prepared in the manner describ-
ed in Example 71 and Example 72 had physical properties s~mi-
lar to those prepared by suspension polymerization described
above.
EXAMPLE 73
Preparatl~on 0~ Gra~t Copolymer Havin~ Polystyrene Sidechains
~nd Polyacrylonitrile Backbone
A solution consisting of 3000 grams of a methacry-
late terminated polystyrene prepared by the procedure o~ Ex_
ample 8 and having a molecular weight of 11,000 dissolved in
12000 grams of dimethyl formamide containing 0.10 gram o~ AIBN
(VAZo~34) are charged into a quart bottleO The bottle is
capped, and purged with nitrogen for 15 minutes. 3105 Grams
o~ acrylonitrile is syringed into the bo~tle, and the clear
solution is rotated for 18 hours at 67Co in a bottle poly-
118
~rrQ~ ~ f 1<
~ 3763~merization bath. The bottle is then post-heated for 5 hours
at 90-95C. The viscous solutlon is then diluted with dimethyl
formamide and the product recovered as a powder by precipita-
tion into methanol~ A film molded ~or 5 minutes at 150Co had
good ~low properties and was yellow, but clearO The absence
of opacity in the molded film clearly demonstrates that little
or no unreacted polystyrene macromolecular monomer was present,
sin^e polyacrylonitrile products containing unreacted poly-
s~yrene are cloudy or opaqueO
EXAMPLE 74
Preparation 0~ Graft Copolymer Havin~ Pol~st~rene Sidechains
And Polyvinyl Chloride Backbone
A methacrylate terminated polystyrene prepared by
the procedure of Example 8 and having a molecular weight o~
about 16,000 and an ~w/Mn o~ less than about lol~ is copoly~
merized essentially to completion with vinyl chloride by
charging the following ingredients in order into a quart
bottle.
Disti~led water 300.0 g.
Lemo~2-88, 5~ solution (PVAL) 300 g,
C i Disodium phosphate 0.40 g.
Lauroyl p~eroxide 0.34 g.
Methacrylate terminated pol~styrene 14.56 g.
Vinyl chloride 85.4 g.
The methacrylate terminated polystyrene and lauroyl
peroxide are added to the aqueous solution of distilled water,
Lemol and disodium phosphate and the quart bottle is chilled
in ice water. Vinyl chloride is condensed in the bottle, and
allowed to evaporate to the correct weight to drlve out airO
Then, the bottle is immediately capped with a butyl rubber
gasketed, Mylar-lined cap. The bottle is rotated in a 55C.
bottle polymerization bath and after l9 hours in the polymer-
ization bath, the excess vinyl chloride is bled of~ and the
'~r~ m~ f k -119o
~3763~
solids content in the bottle is filtered in a Buchner funnel
and rinsed with distilled waterO A yieId v~ 9205 grams of
graft copolymer is obtained, whlch corresp~nds to a 91o 2~
~inyl chloride conversionO A GPC chromatogram of the product
reveals that no detectable unreacted methacrylate terminated
polystyrene occurs at 30.5 counts. (The peak on the GPC
chromatogram for the methacrylate terminated polystyrene
having a molecular weight of 16,000 is 3005 counts~ Accord-
ingly, it is shown that copolymerization of the methacrylate
terminated polystyre~e with vinyl chloride is essentially
complete.
EXAMPLE 75
Preparation Of Graft Co~ol~mer Having Pol~tyrene Sidechains
And P~l~vinyl Chloride Backbone
A graft copolymer of the methacrylate terminated
polystyrene having a molecular weight of about 11,000 and pre-
pared by the procedure in Example 8 with vinyl chloride is
prepared by suspension copolymerization using the ~ollowing
recipe and procedure.
Solution A:
Distille~ water 15000 g,
~q 5% Lemol 42-88 polyvinyl alcohol 105 go
Disodium phosphate 002 g.
Solution B:
Methacrylate terminated polystyrene 5000 gO
Lauroyl peroxide 00125 gO
Vinyl chloride 50O0 g.
Into each of three quart bottles there is charged
150 grams o~ stock solution A above, and the solution is
sparged with nitrogen ~or 30 minutesO The methacrylate ter~
minated polystyrene and lauroyl peroxide are added, and the
bottle is chilled in ice waterO A slight excess of vinyl
chloride is con~nsed in the bottle, and allowed to evaporate
~d~fl~ -120_
~3'~36
to the correct weight to drive out a~O Then the bcttle is
C immediately capped with butyl rubber gasketedg M~lar-lined
capO The bottlefi are rotated in a 50Co bottle polymerization
bath at 30 rpmO Bottles are removed from the bath at 20 5
hours~ 5 hours, and 15.5 hours9 and vinyl chloride is bled im-
mediately upon removal of each bottleO The solids content of
each bottle is filtered in a Buchner funnel and rinsed with
distilled water. The producb is first dried in air9 then
dried in vacuum oven at 50C.
Each of the total product mixtures is dissolved in
THF. One portion of the THF solution is used for GPC analysis,
and the other portion of the solution is added to excess 302
cyclohexane:hexane to precipitate the copolymerO The precip-
itate i8 ~iltered and washed with 3:2 cyclohexane:hexane sol-
vent to remove unreacted macromolecular monomer. The purified
copolymer is dried, and submitted for chlorine analysisO The
copolymer compositions calcula~ed from the chlorine contents
of the ~ractionated products are presented in Table 8 below.
T~BLE 8
Copolymer Compositions ~f 5 ~50 Methacrylate Terminated Pol~-
styrene ~ in,vl Chloride Monomer Charge At Various Con~ersions
VCl C~pol~mer Com~osition
Polymerization Con~ ~ Macromer ~ ~acromer
Time, Hours ~ (From Cl Analvsis) (by GPC)
2.5 4.6 94 87
5~0 9.8 88 89
1505 5504 54 63
(a) Calculated from product yield.
The unfractionated portions o~ the THF solutions are
filtered and me~sured. Volumes o~ the solutions o~ known I ~
solids are injected into the GPC. The unreacted methacrylate
terminated polys~yrene peaks at 31.4 counts o~ the chromato-
-~2~_
Tr~lema~)c
~1037~36
grams are cut out, weighed, and unreacted macromolecular mono~
mer in the samples is determinedO The copolymer compositions
calculated from the GPC data compare ~ell with those calcul~t-
ed fram chlorine analysis and these calculations are also pre-
sented in Table 80
As lt can be seen from the above examplesg the poly-
meri.zable macromolecular monomers of the present invention
offer a convenient route to the preparation of polystyrene
graft copolymers with vinyl chlorideO These graft copolymers
with vinyl chloride do not require processing aidsg since the
melt flow of the graft product is improved over the PVC homo-
po}ymer. Even with low le~els of macromolecular monomer co-
polymerized with vinyl chloride~ milled sheets and molded
specimens have greater clar~ty than .PVC homopolymer controlsO
Macromolecular monomers of the present invention can
be copolymerized with vinyl chloride in solution, bul.k9 or in
conventional suspension polymerization systems with free-
radical initiators, The methacrylate terminated polystyrene
macromolecular monomers have been copolymerized with vinyl
chloride by suspension polymerization at macromolecular mono-
mer levels of 10~ to 50~. The copolymer composition~ of the
low and intermediate conversion samples have been determined
by GPC analysis of the polymer mixture, and by chlorine anal-
ysis of the fractionated samples. A series of GPC chromato-
grams of the product mixtures of polymerizations of a 5~/50
macromolecular monomer~VCL monomer charge at varlous vinyl
chloride conversions have been madeO Analysis of these chro-
m~tograms reveals that the macromolecular monomer peak at 310 4
counts disappears rapidly early in the polymeriz.ationO In all
these copolymerizations, it has been found that most of the
methacrylate termina~ed polystyrene copolymerizes at 10~20%
~122--
' !
1~137~;3$vinyl chloride con~er~i~n. Some low conversion copolymer com-
positlon3 of severai monomer feed composition~, calculated
from GPC and product yield data are presented in Table 90 The
last column in this Table gives the theoretical instant~neous
copolymer composition calculated from the Al~rey-Goldfinger
copolymerization equation (2)9 assuming literature r values o~
methyl methacrylate (Ml), ana vinyl chloride ~M2) for metha-
crylate terminated polystyrene and vi.~yl c~lorideg respective-
ly (rl = lOg r2 = 0.1). It c~n be seen from this data that
the copolymer compositions correspond reasonably well to the
theoretical values, within the limits of experimental accuracy
set by the very low molar concentrations of the macromolecular
monomer double bond.
The relative reactivities o~ ~inyl chlorlde with
vin~l ether-terminated macromolecular monomers and with maleic
half ester-terminated macromolecular monomers prepared by the
procedure described in Examples 5 and 9, respectively9 have
also been determined. The vinyl chloride conversion and re-
activity ratio data with the various macromolecular monomers
are summarized in Table lO. The vinyl ether terminated macro-
molecular monomer appears to copolymerize uni~ormly with vinyl
chlorlde (r2 = 1). The methacrylate terminated macromolecular
monomer and maleic half ester-terminated macromolecular mono-
er copolymerize with vinyl chloride, as predicted from litera-
ture reactivity ratios of methyl methacrylate or maleic esters
with vinyl chloride. Although the macromolecular monomers are
incorporated at much faster rates than vinyl chloride and give
compositionally heterogeneous ccpolymers without resorting to
special polymerization techniques such as gradual addition
the copolymerization studies of the methacrylate or maleic
half ester terminated macromolecular monomers and vinyl
-123~
1~3763~i
chloride sqrve~ to~ s~w that,~ in th,~s~ systems~ ~e ~ ,nal
groups o~ t~e ~4~r~e~u~ar ma3~onl~qrs are gove~ed ~ ç same
copoly~eri~atiqn kln~ti~s ~s th~ ~rr~ond~,ng low m~le~ular
weight mo~Qmer8~
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-126
3~71~36,
EXA,MPLE 76
A 370 gram cha~ge o~ the 701~ m~thacrylate terminated
polyisoprene macromolecular monomer prepared in Example 11 is
vacuum stripped 1~ hours at 50Co on a rot;ary evaporator (601
grams of heptane ~s not removed by stripping)0 The round bot-
tomed flask containing the concentrated macromolecular monomer
is ~ealed with a septum and purged with n~troge~. A solution
eonsisting of 61.2 grams of styrene, 6.1 grams benzene (thio-
s' C phene-free) and 0.31 gram o~ AIBN ~ 0.5~ by weight styrene) is
~ntroduced by syr~nge and the macromolecu~ar monomer is allow-
ed to dissolve, The clear monomer solutio~ is tran~ferred by
syringe into a well-purged 12 ounce bottle containing an aque-
ous polyvinyl pyrrolidone solution (300 grams of water, 0.24
gram Luviskol~ -90 (PVP, 0.3~ by w~lght)). The bottle is cap-
ped, briefly purged with nitrogen) and rotated in ~ 65C.
bottle polymerization bathO A~ter 17.5 hours at 65C., the
bottle is finished at 95C. for-3 hours.
The product beads are filterad on a screen~ washed
with distilled water, and dried at 40C. under vacuum. The
product is milled for 2 minutes at 150Co and 0.40 gram Ionol
CP antioxidant is added on the mill. A yield of 75.8 grams of
transparent milled product is obtained. The styrene ~~onver-
sion is 98~
EXAMP E 77
Preparation Of Graft Copolymer Of Polytetramethylene Ether Di-
isoc,yanate And Pol,vst,vrene Macrometer Terminated With E~
chlorohydrin
Polytetramethylene ether diisocyanate is prepared by
dissolving 290 grams of polytetramethylene ether glycol having
-127-
~nC~
~.~3t~36
an average molecular weight of 29 900 in 600 ml. of tetrahydro-
furan purging this solution with nitrogen and then adding 1~.4
grams (0.05 mole) of a liquid dlisocyanate similar in struc-
f~
~J ture to diphenylmethane diisocyanate and available as Isonate
143L from the Up~ohn CompanyO The bottle containing the$e re-
actantæ is capped and placed in a water bath at 50Co in which
it i8 tumbled at about 30 rpmO After 8 hours, an additional
7.2 grams (00025 mole) of the above liquid d~isocyanate is
added and the reaction is continued for another 8 hours~ At
10 this point, 4035 grams (0.05 mole) of 2,4-tolylene diisocyan-
ate is added and the polymerization is continued under the
same conditions for another 8 hours.
To a solution of 200 grams of polystyrene macromer
terminated with epichlorohydrin and having an average molecu-
lar weight of 12,000 in 100 mlO of tetrahydro~uran and 100 ml.
of water there is added dropwise a sufficient quantity of di-
lute sulfuric acid to ad~ust the pH to 2Ø The resulting
solution is stlrred at 65Co for 8 hours resulting in complete
hydrolysis of the epoxide groups to glycol groups.
A mixture o~ a solution of 60 grams of the above
polytetramethylene ether diisocyanate in 60 ml. of tetrahy-
drofuran, 60 grams of the above polystyrene glycol and 100 ml.
of tetrahydrofuran is placed in a polymerization bottle to-
gether with o.6 gram of stannous octoate. The bottle is cap-
ped, purged with nitrogen and placed in a water bath at 65C~
for 8 hours to produce a graft copolymer. A portion is cast
on a glass plate and allowed to air dry to a flexible, elastic
film. It is cut into small pieces and molded at 150Co and
20-30 psig to a film the tensile strength of which is found to
30 be 1500 psig.
~r~de~ k
-128-
~o37636
EXAMPLE 78
Preparation O~ Gra~t Copol,ym
Diisocyanate And Polyst,Yrene G~
A react~r bottle containing a mixture o~ 87 grams of
polytetramethylene ether glycol having an average molecular
weight of 2,900 and 4.3 grams (0~015 mole) of the liquid di-
isocyanate re~erred to in Example 77 is cappedg purged with
nitrogeny and placed in a water bath at 65co for 8 hours,
The resulting high molecular weight polyurethane glycol is
cooled to room temperature and 43 grams of polystyrene glycol
(prepared as i,n Example 11) having an average molecular weight
of 8,600 and 350 ml. o~ tetrahydro~uran are added and the
bottle capped~ A~ter purging with nltrogen, 5~9 grams (0.023
mole) o~ the above liquid diisocyanate is added and the bottle
is rot~ted at 65C. ~or 8 hours. The resulting graf't copoly~
mer is isolated as a ~lexible, elastic film by depositing it
on a glass plate and air drying. Its tensile strength i5
19 000 psig.
Pol,yblends Emplo,ying Macromolecular
Monomers AB Allo~ing Agents
Polyvlnyl chloride blends with low levels of the
macromolecular monomer/polyacrylate graft copolymers o~ the
invention provide products that are clear~ have improved pro-
cessing and high impact propertiesO Notched Izod impact
strengths o~ 22 ft. pounds/inch are obtained with little loss
in flexural modulus in rigid polyvinyl chloride blends con-
taining as little as 3~ of the macromolecular monomer/poly-
(butyl acrylate) gra~t copolymerO The graft copolymers of
the invention also function as processing aids by improving
polyvinyl chlor~de fusion in milling and compression molding,
The graft copolymers also impart high strength to higher
-129
~lo376~
molecular weight polyvi~yl chloride polymers, such as Vygen
110 and 120, when low levels o~ the graft copolymer macro-
molecular monomer-poly(butyl acrylate) is blended after the
polyvinyl chloride is banded on the millO
Prepara n O~_P lyvinyl Chloride/Macromolecular Monomer Gra~t
Copolymer Polyblend
The ~ollowing ingredients are mixed, and banded on a
150C, lab mill:
Initial ~lend
Vygen*120 (Lot 71-20
polyvinyl chloride) 9600 g.
Stearic Acid 1 0 g
Cadmium Stearate 1 5 g
Barium Stearate lo 5 g~
During the entire milling operatingJ the roll gap i8
ad~usted to maintain a rolling bank, and the stock is cut and
turned every one-half minute, After the initial blend has been
banded on the mill 3 minutes, 4.0 grams of the gra~t copoly~er
having polystyrene sidechains and poly~butyl acrylate) backbone
(30/70) prepared by the procedure o~ Example 70 is added to
the rolling bank and milling is continued an additional 3 min-
utes.
The compression-molded specimens (5 minutes at
170C.) are transparent, and had an average notched Izod im-
pact strength of 22 fto pounds/inch notchJ whereas the control
without the graft copolymer has an Izod impact stre~gth of
Q~4-oo8 ~t. pounds/inchO
In addition to using the rubbery polystyrene/butyl
acrylate graft copolymer as an alloying agent to polymers o~
vinyl chloride, the addition o~ this rubbery component can
also be added to polymers of styrene or styrene-acrylonitrile
copolymers for impact engineering plastics. The polyvinyl
~k -130-
TrQGk~r k
~(~3763~
chloride polyblends with the graft copolymers have exceptional-
ly high impact strength and are useful in pipe, siding~ down-
SpoutsJ cases, etc. This is unexpected because polyvinyl
chloride is known ~or its low impact strength~ Pol~(methyl
methacrylate) also has low impact strength, however* when
methyl methacrylate is either blended or copolymerized with
the lower Tg or rubber macromolecular monomers o~ the inven-
tion, the impact strength is enhanced.
The gra~t copolymers of the invention which ~ave
polystyrene sidechains, particularly those having polyvinyl
chloride backbones~ improve the melt rheology of those poly-
mers having a poor melt rheology and are difficult to process
when small amounts o~ the gra~t copolymer is blended with the
polymer. Examples o~ polymers which can be blended with the
gra~t copolymers o~ the invention to improve the melt rheology
include polymers o~ vinyl chloride, methyl methacrylate,
acrylonitrile, and others.
-131-
