Note: Descriptions are shown in the official language in which they were submitted.
.~
7~
Thi3 invention relates to polymers ~nd, more par
tlcularlyJ to copolymers. In a 9till more partlcular ~en~e,
it relates to certain gra~t copolymer~ which have a wide var-
lety o~ propertie~0
More particularly there i~ de~cribed a gra~t co~
polymer having a linear copolymeric backbone and polymeric
3idechaln~ o~ relatively uni~orm molecular welghtJ each said
sldechain being an integral part of ~aid backbone/ the polnt~
of attachment o~ ad~acent pair~ o~ ~aid sidechalns to said
backbone ~eing separated by unlnterrupted segment~ o~ said
backbone, o~ at least about 20 recurring monomerlc units.
There 1~ also provided a proce~s compriylng pre-
parlng a living polymer, terminatlng 3aid livlng polymer by
reactlon with a halogen-containing epoxide or halogen-con-
taining vinyl compound to ~orm a polymeriæable monomer, and
polymerizln~ said monomer.
Still ~urther, there i disclosed a proces3 ~or the
preparation o~ polymerizable Palymeric monomers comprising
terminatlng a monorunctlonal llvlng polymer by reactlon with
a halogen-contalnlng compound havlng a polymerizable molety.
Mbst polymer~, both natural and synthetic, are in-
compatible wlth one anotber~ Thl~ has become increaslngly
apparent as more and more polymers having particularly good
propertie~ ~or ~peclal u~es have become available, and as e~-
~orts have been made to combine palrs of these polymer~ ~or
the purpose of incorporating the di~rerent~ good properties
o~ each polymer into one product. More o~ten than not? these
e~ort~ have been unsuccess~ul becau3e the reeultlng blend~
have exhiblted an in3tabllity, and in many cases~ the de3ir-
able properties o~ the two polymer~ were completely 108t,
Polyethylene i~ incompatlble with polyisobutylene~ ~or ex-
37~ii35ample, and a blend o~ the two ha3 poorer physical propertie~
than either o~ the homopolymer~. ~hese ~ailu~e~ were at
first attributed to inadequQte mixln~ ~locedures, bu~ even-
tually it was concluded that the failure~ were due 8i~ply to
inherent incompatibilit1esO Alkhou~h it; i~ now believed that
this is a correct explanation~ the genex-al nature of such in-
co~patibility hag remained somewhat unclear, even to the
present. Pol~rlty see~s to be a ~actor, i.e. J two polar
polymer3 are more apt to be compatible than a polar polymer
and a non-polar polymer. Also, the two polymers must be
structurally and composit1onally somewhat similar if they are
to be compatible. Stlll ~urther, a partlcular pair o~ poly-
mers may be compatible only within a qertain range o~ rela~
tive proport1ons o~ the two polymers; outside that range they
are lncompatible.
Desplte the general acceptance o~ the ~act o~ in-
~ compatibility of polymer pairs, there i8 much interest in de-
; vising means whereby the advantageous properties of combina-
tions o~ polymers may be combined lnto o~e product.
One way in which this obJective has been sou~ht in-
volves the preparation o~ block or grart copolymers. In this
way, two d1r~erent polymeric segments, normally incompa~ible
with one another, are Jolned together chemically to give a
sort o~ ~orced compatibility. Thus, the block or gra~t co-
polymer in many instances possesses a combinatlon o~ prop-
erties not normally found in a homopolymer or a random co-
polymer.
Resort to block copolymers or gra~t copolymers,
however, has lts limitations in the case o~ block copolymers
inasmuch as only those monomers can be used which are 8U~-
ceptlble to anionic polymerlzation and this elimInate~ a lot
--2--
:1~37~35
of potential polymeric segments. In the case of those graft copolymers
previously available, they invariably are characterized by the presence of
substantial amount of homopolymer, either of the original homopolymer
backbone or of the grafting monomer. To the extent that such homopolymer
is present, it serves not only as a diluent, but detracts materially from
the ef~ectiveness of the desired properties which are sought to be built
into the graft copolymer.
It is the purpose of the present invention to provlde graft co-
polymers having sidechains of predetermined molecular weights, relatively
free of homopolymers and which have novel combinations of physical pro-
perties.
It is a further purpose of the present invention to provide a
process for the preparation of such graft copolymers.
The present invention provides a graft copolymer comprising a
copolymeric backbone and polymeric sidechains, wherein the sidechains are
comprised of a residue of an anionic initiator, polymerized units of at
least one anionically polymerizable monomer and a copolymerizable end
group which is copolymerized into the backbone of the graft copolymer,
said sidechains having a molecular weight in the range of from 5,000 to
50,000 and a narrow molecular weight distribution; and wherein the backbone
is comprised of polymerized units of a backbone-forming compound and the
copolymerized end group of the sidechains, the points of attachment of the
adjacent sidechains being separated by at least about 20 uninterrupted
recurring units of the backbone-forming compound.
The present invention also provides a process for preparing a
graft copolymer, comprising preparing a living polymer by polymerizing at
least one anionically polymerizable monomer in the presence of an anionic
polymerization initiator to thereby form monofunctional living polymers
having a molecular weight in the range of ~rom 5,000 to 50,000 and a narrow
molecular weight distribution, reacting the monofunctional living polymer
~ ~ _ 3 -
1~3~ 5
with a halogen-containing epoxide or halogen-containing vinyl compound to
form a macromolecular monomer having a copolymerizable end group, and
thereafter copolymerizing said copolymerizable end group with a backbone-
forming compound.
These purposes of the invention are accomplished by a graft co-
polymer having a linear copolymeric backbone and polymeric sidechains of
relativ~ly uniform molecular weight, the points of attachment of adjacent
pairs of said sidechains to said backbone being separated by uninterrupted
segments of said backbone of at least about 20 recurring monomeric units.
The graft copolymers herein differ from those previously available
in that the polymeric sidechains are prepared first, by the method of
- anionic polymerization. Such method produces a living polymer which may
be terminated by reaction with a halogen-containing compound, and by selection
- 3a -
7~3~
of the appropriate terminating agen~, a polymer having a
te~minal polymerizable group may be obtained. This polymer
may itself be further polymerized to form graft copolymers of
the kind described above. Alternatively, copolymerization of
this high molecular weight polymerizable compound with a sec-
ond compound, usually of relatively low molecular weigh~, also
yields a graft copolymer of this type.
Particularly useful graft copolymers of this type
are those in which the copolymeric backbone and polymeric
sidechains are thermodynamically incompatible. Such graft
copolymers are obtained when the uninterrupted polymeric seg-
men~s of the copolymeric backbone and of the polymeric side-
chains are large enough to impart to the graft copolymer the
physical properties characteristic of the polymers which cor-
respond to these polymeric segments. In general, for this
purpose, the polymeric segment, whether it be a part of the
backbone or of the sidechain, should consist essentially of
at least 20 uninterrupted recurring monomeric units, and
preferably at least about 30 recurring monomeric units.
The graft copolymers of the present invention
assume a "T" type structure when only one sidechain is copoly-
merized into the copolymeric backbone. ~lowever, when more
than one side chain is copolymerized into the backbone poly-
mer, the graft copolymer may be charac~erized 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
1'
a a a
a a a
a a a
r
~ ~376~35
wherein "a" represents a substantially linear, uniform mole-
cular weight polymer or copoly~er having a sufficient mole-
cular weigh~ such that the physical properties of a~ leas~ one
o~ the substantially linear polymers are manifest; "b"
represen~s a reacted and polymerized end group chemically
bonded to the sidechain, "a", which is integrally polymerized
~nto the backbone polymer, and "c" is the backbone polymer
having uninterrupted segments of sufficient molecular weight
such that the physical properties of the polymer are mani-
1~ fest.
The preparation of these graft copolymers begins,
as noted above, with anionic polymerization o~ a polymeriz-
able monomer. In most instances, such monomer is one having
an olefinic group although it may be an epoxy or thioepoxy
gro~p.
Those monomers susceptible to anionic poly~eriz-
ation are well known and the present invention contemplates
the use of all anionically polymerizable monomers. Illus-
trative species include styrene, alpha-methyl styrene, acryl-
amide, N,N-lower alkyl acrylamides, N,N-dilower alkyl acryl-
amides, acenaphthalene, 9-acrylcarbazole, acrylonitrile,
methacrylonitrile, organic isocyanates including lower alkyl,
37~3S
phenyl, lower alkyl phenyl and halophenyl i~Ocya~ate3, or-
ganic diloscyanates includlng lower alk~lene, phenylene and
tolylene diisocyanatesJ lower alkyl and allyl aorylate~ and
methacrylates, lower ole~lns, vinyl estler~ o~ aliphatic car-
boxyllc acids such a~ vinyl acetate, vinyl propionate, vinyl
octoate, vin~l oleate and vinyl stearat~J vlnyl benzoate,
vlnyl lower alkyl ethers, vinyl pyridines, isoprene, buta-
dlene and lower alkylene o~idesO The term "lower" is used
above to denote organic groUPg containing eight or ~ewer
lQ carbon atOm3.
The catalyst rOr these anionic ~olymerizations is
an alkall metal alkyl, the alkyl being a lower al~yl, i.e ,
having eight or ~ewer carbon atom~. The butyl lithiums are
pre~erred particularly ~ec-butyl lithium, Lower alkyl
lithiums and lower alkyl sodiumes are especially use~ul,
Other suitable catalysts include i~opropyl lithlum, ethyl
sodlum, n-propyl sodium, n-butyl potassium, n-~cty~ potas~ium,
n-butyl lithiumJ ethyl llthlum, t~butyl lithium and 2-ethyl-
hexyl lithium. The alkali metal alkyls are either available
commercially or may be prepared by known methods Phenyl
lithium, phenyl sodium, etc. may also be u~ed a~ a catalyst
and they are llkewise conveniently availableJ by the reactlon
o~ bromo benzene and the approprlate alkall metal
The amount of catalyst iB an important ~actor in
anlonlc poly~erlzatlon because it determlne~ the molecular
weight of the living polymer. I~ a small ~roportlon o~ cat-
alyst 18 u~ed, with respect to the amount o~ monomer, the
molecular weight of the llving polymer will be larger than i~
a large proportion o~ catalyst is used Generally, it i9 ad-
vi~able to add cataly~t dropwi~e to the monomer ~when that isthe selected order o~ addition) untll the persl~tence o~ the
-6-
763~iicharacterlst1c color o~ the orKanic an~on, then add the cal-
culated amount o~ catalyst. The prellm1nary dropwi~e addi-
tion serves to destroy contaminant~ and thu~ permits better
control o~ the polymerization.
The anionic polymerization must be carried out
under care~ully controlled condltion~, so as to exclude moiR-
ture and other contaminants. The monomer and catalyst should
be ~reshly purl~ied and the apparatus in which the polymeriz-
ation ls to be carried out should be care~ully cleaned
Techniques for purl~ying the reactants and cleaning the re-
action equipment are well knRwn and need not be set ~orth
here, The alkali metal cataly~t ~ay be added to the monomerJ
or the monomer may be added to the catalyst, A solvent ~en-
erally i9 u~ed to ~acilitate heat tran~er and adequate mix-
ing of cataly~t and monomer, The ~olvent should be lnert,
Hydrocarbons and ethers are pre~erred, lncluding benzene,
toluene, dimethyl ether, diglyme, glyme~ diethgl ether,
tetrahydro~uran, N-hexane, cyclohexane and N-heptane. The
temperature of the polymerization will depend on the monomer.
The polymerization of styrene i8 generally carrled out at
~lightly above room temperature; the polymerization of alpha-
methyl ~tyrene preferably i9 carried out at -80C. The tem-
perature Or the anionic polymerizatipn i8 not a critical fea-
ture of th1s invention.
The polymeric product is a so-called "llving poly-
mer", i.e., it is not terminated in the usual sense of that
word as it is used in polymer chemigtry, but iR ~usceptible
of further reaction including further polymeriæationO The
anionic polymerizatlon 1~ lllustrated by the ~ollowin~ equa-
tion, where styrene ls polymerized by ~ec-butyl lithium:
Bec-BuLi + n C~ = CH _~ sec-Bu- ~C~ CH - -C~ CH Li
L~ ~
; . n-l
I~ styrene 18 added to the above living polymer, the poly-
merizatlon i9 renewed and the chain gro~ until no more
monomeric styrene remains. A~ternatively, lf another dif-
rerent anionically polymerlzable monomer 18 added, ~uch as
butadiene, the above living polymer initlate~ the polymeriza~
tion of the butadiene and the ul~imate llvlng polymer which
re~ults Consl~ts o~ a poly~tyrene segment and a polybutadlene
segment, The llving polymer may be termlnated bg reaction
wlth a halogen_conta~nlng compound, Termination o~ thq above
living polystyrene wlth methyl iodide is lllust~ated by the
~ollowin~ equatlon:
sec-Bu-C~ C~- C~ CM- ~ + CH3I-~sec-Bu - ~C~ C~- -C~ CXC~ + LiI
~ L ~
n-l n-l
~ ivlng polymers are characterized b~ relatively uni-
Porm molecular weight, i.e.l the di~tributlon o~ molecular
weights in an average l~vlng polymer i~ quite narrow. Thi8
i&-in marked contrast to the typical polyme~, where the
molecular weight distributlon 1~ quite wide.
An ~mportant ~eature o~ this lnvention 18 the uni-
~ormlty of molecular welght o~ the ~idechaln~ o~ the ~raPt
copol~mer and this uni~ormity of mQlecular wei~ht lnhere3 in
the livlng polymer whlch i8 prepared as the flr~t step in the
overall synthe~is o~ these gra~t copolymer~. A p~rtlcularly
~37~35
Rreferred embodiment of this înventîon resides in graft co-
polymers containîng sîdechains havîng an average molecular
weight of from about 5,000 to about 50,000.
The lîving polymers herein are terminated by reac-
tion with a halogen-containing compound which also contains
either a polymerizable olefinic group or an epoxy or thio-
epoxy group. Suitable halogen-containing terminatîng agents
include vinyl halo alkyl ethers wherein the alkyl groups
contains six or fewer carbon atoms, vinyl esters of halo-
alkanoic acids wherein the alkanoic acîd contains six or
fewer carbon atoms, allyl halides, epihalohydrîns, acrylyl
halides, methacrylyl halides, halomaleîc anhydrîdes, halo-
maleate esters, vinyl halides and halovinyl silanes. The
halo group may be chloro, fluoro, bromo or îodo; preferably,
lt is chloro.
Termination of the living polymer by any of the
above types of teminating agents is accomplished sîmply by
adding the terminating agent to the solution of living poly-
mer at the temperature at which the living polymer is pre-
pared. Reactîon is immediate and the yield is theoretical.
A sllght molar excess of the terminating agent, with respect
to the amount of catalyst, is used although the reactîon
proceeds on a mole-for-mole basis.
~1~37~3S
The following equations illustrate typical reactions in accordance
with the prac~ice of ~he presen~ invention:
Living Polymer:
--Rl - Rl
R - CH2 - R n R2
Terminating Agents:
(a) X R3 - o _ C = CH2
R
(b) X - R3 _ C - O C = CH2
. R4
~c) X ~3 - f = C~2
R4
~d) X - R3 - ~
(e) X - CC = CH2
R4
(f) X~ ----CO ~
R4{;--co /
(g) X--C~CoOR4
R4{---COOR
(h) X - R3 - CH - \ CH2
~0
~i} X - C - C
Il \O
R4- C - C ~
- 10 -
1 ~37~;i3S
Rl R
(a) R----Cl{ - C------CH2 C----R3--- OC = C~
R2 R4
Rl I Rl o
(b) R--_CH2- R2~--Cl-l _ C--R3 C OC = CH
Rr ~Rl
(c) R--- CH - C ---CH--- C--R3--C = CH
Rl Rl .
(d) R--~ C.H2 , --CH2----C-- R3-- C----CE12
R2 n R2 R4
Rl Rl o
(el R--CH2~ C R2 R4
Rl R
(f) R - CH2 C ---CH2--C C--CO
R2 n R R4--C _ CO
Rl Rl
(g) R--- CH -- C - CH2--C--C - CoOR4
R nR R--C COOR
( ) iH2 C2,~ C112 - C - R - CH - CH2 1~2o
Rl Rl OH Oll
C112 ~ c----CH2 - C - R CH C 2
~.~
1~3~63~
(i) R C~lz - C 2 C - R - C - C ~ ~12o
n ~ O
R 1 R1
R ~ C~ - C ~ C~l - C - R~ C COOH
In the above equations, R, R1, R2 and R4 are selected from
the group consisting of hydrogen and lower alkyl and aryl radicals; X is
halogen and R3 is a valence bond or a lower alkylene radical. Preferably,
R will be lower alkyl, such as sec-butyl; Rl will be either hydrogen or
methyl; R2 will be phenyl; and R4 will be either hydrogen or lower alkyl
radical.
In some instances, because of the nature of the living polymer
and the monomer from which it is prepared, or because of the nature of the
terminating agent, it is advisable to "cap" the living polymer with a re-
actant such as a lower alkylene oxide, i. e., one having eight or fewer
carbon atoms, or diphenyl ethylene. This "capping" reaction yields a product
which still is a living polymer, but which is less susceptible to reaction
with functional groups or any
~ - 12
1~37~35
active hydrogeng Or a terminating agent. Thus, ~or example,
acrylyl chloride while it act~ ~8 a terminating agent because
of the pre~ence o~ the chlo~ine ato~ in its s~ructure, al~o
provide a carbonyl group in the termlnated polymer chain
and this carbonyl ~0up may provide a center rOr attack by a
second living polymer. The u~e o~ acrylyl chloride as a ter-
minatlng agent is much ~acilitated 1~ the living polymer ls
~irst capped, then reacted with the acrylyl chloride. The
resulting living polymer i8 a substantlally pure vinyl ester,
i.e., a living pQlymer which has been terminated by a mole-
cule Q~ acrylyl chloride. If no capping agent i8 used in
this intermedlate step, tbe resultlng polymer either has
; twice the expected molecular welght or contaln~ some chlorine,
lndicatlng that ~ome Q~ the living polymer has been terminated
by reaction with a second living polymer or with one Or the
actlve hydrogens o~ the acrylyl chloride.
A particularly prererreq termlnating sgent is
ethylene oxide. It reacts with the llving polymer, with the
destruction Or its oxirane range as rOllow8:
seo-Bu ~ H ~ ~ G ~
L1 + C~ /CH2 --~ sec-Bu ~ ~ ¦ B ~ CB2CB20 Ll
The above equatlon hows the reactlon o~ ethylene oxide a~ a
capping reagent with a living polymer prepared by th~ poly-
merization Or ~tyrene with ~ec-but~l lithiu~.
- 13 -
~ ~ 3~ S
m e cappin~ reaction is carried out quit~e simPly,
as in the case of the terminating reaction~ by adding the
capping reactant to the living polymer at ~olymerization
temperature. ~he reaction occuræ immediately. As in the
case o~ ~he termination reactant, a ~ ht molar excess o~
the capping reactant with respect to the amount o~ catalyst,
is used. m e reactlon bccurs on a mole-~or-mole basi~.
When an epihalohydrin i8 uæed as the term1nat1ng
reagent, the resulting polymer contains a termlnal epoxy
group. Thi~ terminal epoxy group nay be converted to the
corresponding glycol by warming with a~ueoua sodium hydrox-
lde The resulti~g glycol may be converted to a copolymer
by reaction with a high molecular welght dicarbo~ylic acid
wh~ch may be prepared, e g " by the polymeriza~lon o~ a gly-
aol or diamine with a molar excess of phthalic anhydride~
maleic anhydride, succinic anhydride~ or the like. It may
also be reacted with a dilsocyanate to ~orm a polyurethane,
The diisocyanate may be e.g., the reaction product o~ a poly-
ethylene glycol havin~ an average molecular weight o~ 400
with a molar excess o~ phenglene diisocya~ate.
In another embodiment Or the invention, an organ1c
epoxide is copolymerized with a term~nated living polymer
containing an epoxy or thioepoxy end group. The graft co-
polymer which results is characterized by a backbone having
uninterrupted segments of at least about 20 and Pre~erably at
least about 30 recurring units Or the organic epoxide, Pre-
rerred organic epoxides include ethylene oxlde, propylene
oxide, butylene oxide, hexylene oxide, cyclohexene epoxide,
and styrene oxlde, i eO, tho~e havln~ 8 or fewer carbon
atom~.
When a halomaleic anhydride or halomaleate ester is
- 14 -
lQ~317~3~i
used as the terminating agent, the resulting polymer conta1ns
ester groups which may be converted by hydroly~1s to carboxyl
group~0 The result1ng dicarboxylic polymer may be copolymer-
ized w1th glycols or diamines to form polyegters and poly-
amides hav~ng a grart copolymer structureO
It will bç noted that the reaction o~ the living
polymers herein with the above term1nat1ng reagents yields
products whichJ while they are not living poly~er~, are them-
selves ~urther polymerizableO Such ~urther polymerization
may proceed either through the double bond or the glycol por-
tion or epoxy portion of the terminating reagent, so that the
terminatlng reagent thus acts as a ~ ln the ~ormation o~ a
gra~t copolymer It will be noted ~urther that t~e~e gra~t
copolymergJ while their ~tructure conforms generally to that
o~ the gra~t copolymer3 o~ the prior art, are prepared in a
notably different manner than the method of preparatlon of
the gra~t copolymers o~ the prior art. Furthermore, they are
significantly dir~erent, structurally~ Prior to the inYen-
tion herein, gra~t copolymers were prepared by synthe~iz1ng a
linear "backbone"~ then grafting onto this backbone, growing
polymeric chains, and the ultimate result wa~ a backbone hav-
ing several pendant polymeric chains. The graft copolymers
o~ this invention, on the other hand, are prepared by ~irst
synthesizing these pendant polymeric chain~ (the liv1ng
polymers) then polymerizing the terminal pQrtions of the~e
polymeric chain~ into a backbone That is, the pendant
chains, 1.e.) sidechains, are synthesi~ed ~irst, then the
backbone. ~he sidechains are thus 1ntegral partg o~ the
backbone. Obviously, although the two type~ o~ gra~t copoly-
mers resemble each other eenerally, they are di~erent compo-
sitlonsg not only because they are prepared hy s1gni~icantly
- 15 -
-
~037~35
dif~erent processes, but because the pendant pol~merlc chains
o~ the gra~t copolymers o~ thi~ lnvention are Or relatlvely
uni~orm, mlnimum length, and are each an integral part Or the
backbone, and becau~e the backbone contains polymerlc ~eg-
ments o~ certain minlmum length. The~e characteristics ~on-
tribute materially to the advantageous properties which in-
here in these novel grart copolymers
A~ noted earller, the gra~t copolymers o~ this in-
ventlon have unique properties and unique combinations of
propertie~ These unique properties and combination~ o~
properties arç made possible by the novel process hçrein
whlch ~oroes the compatibil~ty o~ otherwise lncompatible
polymer segments. ~hus, the advantageous propert~es of a
polystyrene may be combined with thq ad~antageous propertie~
o~ a polymethyl acrylate, al~hough these two p~lymers nor-
mally are incompatible w1th one another and mere phy~ical
mixtures of them have very little ~trength and are not use-
ful, To combine these advantageou~ proper~ies in one prod-
uct, it is neceqsary that the dlfferent polymeric ~egments
be Present as relatively large sçgment~. The properties Or
poly~tyrene do not beoome apparent until the polymer con-
3ists essentially o~ at least about 20 recurring monomeric
unit~, Thls same relationship appl1eR to ~he polymeric seg_
ments present in the gra~t copolymers herein~ i,e., i~ a
gra~t copolymer comprisin~ p~lystyrene ~egments i~ to be
characterlzed by the advantageous propertie~ o~ poly~tyrene,
then those polystyrene segments must, lndlvidually, con~1s~
essentially Or at leaRt about 20 recurring monom~ric units.
Thi~ rela~ionship between the physical properties a~ a poly-
meric ~egment and its minlmum size 1~ applic~ble to thepolymeric segments o~ all gra~t copolymers herein. In gen-
16 -
1~3~35
eral, the minimum q1ze of a polymeric segment whlch 1~ a~so-
ciated with the appearance o~ the phys1cal properties Or th~t
pol~mer in the gra~t copolymer~ herein :i9 that which con-
sists o~ about 20 recurrlng ~onomeric ull1ts. Pre~erably~ as
noted earlier herein, the polymeric segments, both o~ the co-
polymeric backbone and of the sidechain~, will cons1~t essen~
tially of more than about 30 recurring monomer units. These
polymeric segment~ may themselve~ be homopolymerlc or they
may be copolymeric. Thus, a graft copolymer o~ thi~ inven-
tion may be prepared by the copolymerization o~ methyl metha-
crylate, lauryl methacrylate and a terminated polyqtyrene
containing a polymerlzable olerinic group, The u~interrupted
polymeric segment~ o~ the backbone o~ such a gra~t copolymer
w1ll be copolymeric segments o~ methyl methacrylate and
lauryl methacrylate,
The grart copolymers comprising polyme~ic segments
having rewer than about 20 recurring monomeric units areJ
nevertheless, use~ul for many applications, but the pre~erred
graft copolymers are those in which the various polymeric
~egments have at least about 20 recurrln~ monomeric units.
Although, as indicated, the grart copolymera herein
are characterized by a wide variety o~ physical properties,
depending on the particular monomers used ln their prepara-
tion, and also on the molecular weights o~ the various poly-
mer segment within a particular ~raft copolymer, all o~ these
gra~t copolymers are use~ul, as a minimum, as tough flexlble,
sel~-supporting ~ilms. These ~ilm~ may be used as ~ood-
wrapping mate~ial, painters' droP-Cloth~, protective wrapping
~or merchandise disp1ayed ~or sale and the like~
The invention i8 illu6trated further by the follow-
ing examples, In each case, all material~ should be pure and
- 17
1~3~3~ii
care should be taken to keep the reactant mlxture~ dry and
rree of contamina~ts. All parts and percentages, u~less ex-
pre~sly stated to be otherwise, are by weight.
EXAMPIE
A solutlon o~ one drop of diphenyl ethylene at
40Co is treated portionwise with a 12~ ~301ution D~ t-butyl
lithium in pentane until the persistence Or a light red
colorg at which point an addi~ional 30 ml~ (0.04 mole) o~ the
t-butyl lithium solution is added, followed by 312 g, (3.0
moles) o~ styrene. The temperature of the polymerizatlon
mixture is maintaineq at 40C. ~or 30 minutes whereupon the
living polgstyrene is terminated by treatment with ~ mlO
~o.o8 mole) o~ vinyl-2-chloroethyl ether. The re3ulting
polymer i8 preclpitated by addition Or the benzene solution
to methanol and the polymer is separated by ~iltration, Its
number average molecular wei~ht, as determined by vapor phase
osmometry, ls 7,200 (theory: 7870) and the moleculare weight
dlstributlon is very narrow, i.e " the Mhi~h 1~ less than
1 oO6 ~
AMPLE 2
Preparation o~ Polystyrene Terminated With Vinyl Chloroacetate
A solution o~ one drop o~ diphe~yl ethylene in 2500
mlO o~ cyclohexane at 40C. is treated portionwise with a 12
solution o~ ~ec-butyl lithium in cyclohexane until the per-
sistence o~ a light red color, at which point an additional
18 ml. (0.024 mole) o~ the sec-butyl lithium is added, ~ol-
lowed by 312 gO (3,0 moles) o~ styrene. The temperature of
the polymerization mixture is malntained at 40C. ~or 30 min-
utes whereupon the living polyBtyrene i8 capped by treatment
with 8 ml. (0 040 mole) o~ diphenyl ethylene, then terminated
by treatment with 6 mlO (0.05 mole) of v1nyl chloroacetate
-- 18 --
1~3~7~;35;
The resulting polymer is precipitated by addition o~ the
cyclohexane solution to methanol and the polymer is separat-
ed by filtratlonO It~ number average molecular weight, a~
determlned by vapor phase osmometry i5 12,000 (theory:
139265), and the molecular weight dlstr~bution 1s very nar-
row, iOe.9 the M~/Mn is less than 1006.
EXAMPLE 3~
Preparation of Polystyrene Terminated with ~pichlorohydrin
A benzene solution o~ living polystyrene 18 pre-
~; 10 pared ln Example 1 and terminated by treatment w1th 10 g.
(OolO mole) o~ eplchlorohydrin. The resulting terminated
polystyrene 1s precipitated with methanol and separated by
~iltration. Its molecular weightJ as shown by vapor phase
osmometry is 8,660 (theory: 7,757) and its number average
molecular weight distribution is very narrow.
EXAMPLE 4
Preparation of Poly(~lpha-methyl styrene~ Terminated With
Vinyl Chloroacetate~
A ~olution of 357 ~. (3.0 moles) Or alpha-methyl
styrene in 2500 ml. o~ tetrahydro~uran is tre~ted dropwise
with a 12% solution Or t-butyl lithium in pentane until the
persistence o~ a light red color. Thereupon, an additional
15.0 ml (0 03 mole) of the t-butyl solution is added, re-
sùlting in the development o~ a bright red color. The tem-
perature o~ the mixture i8 then lowered to -80C., and a~ter
30 minutes at that temperature 5.6 ml~ of diphenyl ethylene
is added~ The resulting mlxture is poured into 5~0 ml.
(0.04 mole) o~ vinyl chloroacetate and the thus terminated
poly(alpha-methyl styrene) is precipitated with methanol and
separated by ~iltration. Its ~umber average molecular weight,
as determined by vaPor pha~e osmometry, 1R 14,280 (theory;
- 19 -
~ Q37~3S
129065) and the molecular we1ght distr1bution 1s very narrow.
EXAMPLE 5
Preparation of Poly(alpha-methyl styrene ~
A solutlon Or 472 g. (4.0 moles) Or alpha-methyl
styrene in 2,500 mlO o~ tetrahydro~uran i~ treated dropwise
with a 12% solution of n-butyl lithium in hexane until the
perslstence Or a light red color. An additional 30 ml, of
this n-butyl lithium ~olution is added resulting in the de-
velopment o~ a bright red colorl The temperature o~ the mix-
ture is then lowered to _80C.9 and a~ter 30 minutes at this
temperature 4.5 g. (o.o6 mole) Or allyl chloride is added,
The red color disappears almost immediately indicatin~ ter-
mination of the living polymer. The resulting colorles~
solution ~ poured into methanol to preclpltate the terminat-
ed poly(alpha-methyl styrene) WhiCh is shown by vapor phase
osmometry to have a number average molecular weight of 11JOOO
(theory: 12J 300).
EXAMPLE 6
.
Preparation of Polystyrene Terminated With Methacrylyl
_
A solution o~ 0.2 ml. o~ diphenyl ethylene in 2,500
ml. o~ benzene there 18 added dropwise a 12% solution o~ n-
butyl lithium ln hexane until the persistence o~ a light red-
diæh brown colorO An additional 24 ml. (0.031 mole) o~ thi~
n-butyl lithium solution is added, and then, 416 g. (4.0
mole) of styrene, resulting in the development of an orange
color. A temperature of 40C. i9 maintalned throughout by
external cooling and by controlllng the rate at which the
styrene is added. mis temperature is mainta1ned for an ad-
ditional 30 minutes a~ter all of the styrene has been added,
and then is lowered to 20Co whereupon 4.4 g. (0.1 mole) o~
- 20 -
~ 3~3Sethylene oxide 1s added, cau~ing the ~olution to become
colorle~sO T~e living poly~tyrene i8 terminated by reactlon
w1th 10 mlO ~Ool mole) o~ me~hacrylyl chloride~ The result-
ing polymer has a number average molecular weight~ as ~hown
by vaPor phase 03mometry, of 103 OOOo
Acrylyl chloride can be ~ubstituted ~or methacrylyl
chloride in the above procedure to'glve an acrylic acid e~ter
end group on the polystyrene chain.
Examples 1-6 show the preparation o~ termlnated
li~ing polymers. The~e are used as starting ma~erials in the
procedures of Examples 7-14 to prepare the graft copolymer~
herein The terminated living ~olymer~ appear as sidecha1ns
in the gra~t copolymers, wi~h the polymerlzable end group o~
the terminated living polymer end1ng up a~ an integral part
o~ the backbone of the graft copolymer.
EXAMPLE 7
Preparation o~ Gra~t Copolymer ~rom Polystyrene Terminated
Wlth Vlnyl-z-~hloroet~yl ~ther~'and ~thyl ~cr~y-late ; '
' To a solution of 18 gO o~ octylphenoxy polyethoxy
ethanol (emulsif1er) in 300 g o~ deionized water there ls
added, with v1gorous agitation in a Waring Blender, a 801U~
tion o~ 30 g o~ the polystyrene product o~ Example 1 and 70
g. of ethyl acrylate. The resulting dispersion 1s purged
with nitrogen, then heated with stirr1ng at 65C. whereupon
o l g~ of amm~nlum persul~ate i3 added to initiate polymer-
izatlon. Thereupon, 200 g Or ethyl acrylate and 0 5 g of
2~ aqueous ammonium per~ulfate solutlon are added portionwise
over a period of three hours, the temperature being maintained
throughout at 65C. The reRulting grart copolymer emulsion
1s cast on a glass plate and allowed to dry in air at room
temperature to a ~Iexible sel~-suPPortlng ~llm The ~llm is
- 21 -
15;~37~3~
shown to continue polystyrene segments by extraction with
cycl~hexane which dlssolves polystyrene; the cyclohexane
extract on evaporation yields no res~dueD
EXAMPLE 8
Preparation o~ Graft Copolymer Or Poly(alpha-methyl styrene~
~erminaté~'WI~h~VI-vl Chlo'roac'èta~e''~
A ~olutlon o~ 50 g~ o~ poly(alpha~methyl ~tyrene)
macromer terminated with vinyl chLoroacetate and having an
average molecular weight of 129600 and 450 g. o~ butyl acry-
late in 1,000 g~ o~ toluene is purged with nitrogen at 70G,
then treated with 1 g. o~ azobisisobutgronitrile. The tem-
perature is maintained at 70C. ~or 24 hours to yield a
solution o~ gra~t copolymer which 19 cast a~ a ~ilm on a
gla~ plate, The dried ~ilm ls slightly tack~ and i~ sho~n
to contaln polystyrene segments by extraction w1th cgclo-
hexane and evaporatlon ~f the cyclohexane extract, as above.
EXAMPLE 9
~ .
Preparation o~ Graft Copolymer o~ Pol~styrene Termlnated With
~pichlbrohy~rin and I'sobutyIPne ~~ ~' '`
--
To a solution o~ 20 g, o~ polystyrene macromer ter-
minated w1th epichlorohydrin and having an average molecular
weight o~ 10,000 in 1,000 ml. of toluene at -70C" there i8,
added 80 g. of isobutylene. 45 Ml. o~ boron tr1chloride
ethyl ether complex is added slowly, the temperature being
maintained at -70C. throughout. Polymerizatlon occurs as
the catalyst is added and i8 complete almost immed$ately
a~ter all of the catalyst has been added~ The resulting
graft copolymer is obtained by evaporating away the toluene
and washing the resi~ual sol1d with methanol.
22 -
~ 1~37635
EXAMPL~ 10
Preparation o~ Gra~t Copolymer of Polystyrene Termlnated ~ith
~5p~:chlorohy~rln and Isobutylene
.
To 13000 ml. o~ methyl chloride at -70Ct there is
added 10 g, Or poly3tyrene macromer terminated with eplehloro-
hydrin, having an average molecular weight of 10~000. To
this resulting solution maintained at -70C.~ there i8 added
concurrently and dropwlse, a solut1on of 2 g. of aluminum
¢hloride in 400 mlt of methyl chloride and 90 g. o~ i~obutyl-
ene. The time required for these additions is one hour andat the end of this time polymerization is subQtantial.~ com-
plete. The resulting insoluble gra~t copolymer is isolated
by evaporatlon of the methylene chloride,
AMPL~ 11
Preparatlon o~ Gra~t Copolymer o~ Polytetramethylene Ether
Di~s'ocyanate-an~ ~olystyrene Macromer ~ermln~e~ w~n~
plchlorohydr1n
Polytetramethylene ether dlisocyanate ls prepared
by disæolving 290 g. of polytetramethylene ether glycol hav-
ing an average mo~ecular weight of 2,900 in 600 ml. o~ tetra-
hydrofuran purging thls solution with nitrogen and then add-
ing 14,4 g. (0.05 mole) of a liquid diisocyanate similar in
structure to diphenylmethane diisocyanate and available as
Isonate 143L from the UpJohn Company, The bottle containing
these reactantR is capped and placed in a water bath at
50C. in which lt is tumbled at about 30 rpm. A~ter 8 hours,
an additional 7.2 gO (0.025 mole) of the above liquld dilso-
cyanate is added and the reaction is continued for another 8
hours~ At this point, 4.35 g. (0.05 mole) o~ 2,4~tolylene
~diisocyanate is added and the polymerl~ation i~ continued
under the same conditions ~or another 8 hours.
To a solution of 200 g. of polystyrene ~acromer
- 23 -
~ 37635
terminated with epichlorohydrln and having an average molecu~
lar weight o~ 12,000 in 100 ml. o~ tetrahydro~uran and 100
ml. of water there i~ added dropwise a ~uf~icient quantity o~
dllute sulruric acid to ad~ust the pH to 2~0. The resu1ting
solution i8 stirred at 65C. ~or 8 hours rçRulting ln com~
plete hydrolysis of the epoxide group~ to glycol groups.
A mixture Or a solutlon o~ 60 g~ Or the above poly-
tetramethylene ether diisocyanate in 60 ml. of tetrahydro-
~uran, 60 g. o~ tbe abave polystyrene glycol and 100 ml. o~
tetrahydro~uran i8 placed in a polymeriæation bottle together
with oO6 g. of stannous octoateO The bottle is oappecl,
purged w1th nitrogen and placed ln a water bath at 65C. rOr
8 hours to produce a graft copolymer~ A portlon 1s cast on
a glass plate and allowed to air dry to a ~lexible, elast1c
~ilm. It 18 cut into ~mall p1eRes and molded at 15~C. and
20-30 psig. to a fllm the tensile strength o~ which is found
to be 1500 psig.
EXAMPLE 12
,
Preparation of Graft Copolymer of Polytetramethylene Ether
~IIsocyanate an~ -Pol~styrene ~-lycol - -
A reactor bottle containing a mixture of 87 g, o~
polytetrameth~lene ether glycol having an average molecular
weight o~ 2,900 and 4,3 g, (0,015 mole) o~ the liquid diiso-
cyanate re~erred to in Example 11 i8 capped, purged with ni-
trogen, and placed in a water hath at 65C. for 8 hours, The
resulting hlgh molecular welght polyurethane glycol is cooled
to room temperature and 43 g. of polystyrene glycol (prepared
as in Example 11) having an average molecular weight o~ 8,600
and 350 ml, o~ tetrahydro~uran are added and the bottle cap-
ped A~ter purging with nitrogen, 5.8 ~. (0.023 mole) o~ theabOve 11quid diisocyanate is added and the bottle i8 rotated
- 24 -
at 65C. for 8 hours. The resulting gra~t copolymer i~ iS4-
lated as a fl`exible, elastic ~ilm by depoRiting it on a glass
plate and alr dxying It~ tensile ~tre~th i~ 1,000 p~ig.
EXAMPLE 13
Preparation o~ Graft Copolymer o~ Poly~tyrene M~cromer
~3~r~~Fy~re
A mixture o~ 21 g. of polystyrene macromer termin
ated with methacrylyl chloride and having an average molecu-
lar welght o~ 10,000 prepared a~ in Example 6. 28 g. o~
ethyl acrylate and 0.035 g, o~ azobl~isobutyronltrile i~
prepared at room temperature and kept ~or 18 hours, under
nitrogen9 at 67C. The re~ultlng product i~ a tou~h,
opalescent material which can be molded at 160C. to give a
clear, tough, transparent sheet,
EXAMPLE 14
Preparatlon o~ Gra~t Copolymer ~om Poly~alpha-methyl 8~ rene~
A solution Or 20 g. of ~oly(alpha-methyl styrene)
macromer terminated wlth allyl chloride and havlng an average
molecular weight o~ ~,000 prepared as in Example 5 ln 100
ml. Or cyclohexane i8 prepared and t~eated wlth 5!5 ml. Or
o,645 M diethyl aluminum chloride in hexane and ~ ml. o~
vanadium oxytrichloride~ then pressured with ethylene to 30
Psig. This sy~tem i8 agitated gently ~or about one hour at
3~C. whereupon a polymerlc material precipitates ~rom the
solution. It i8 reqovered by ~iltration and pressed i~to a
thln transparent rilm which i~ tought and ~lexible.
- 25 -
