Note: Descriptions are shown in the official language in which they were submitted.
10~0~4~ ~ ~
This application is a divisional of copending Canadian Application ~~
Serial Number 135,079 filed February t8, l9?2. ;
This invention pertains to a process for the preparation of poly-
merizable polymeric monomers comprising terminating a monofunctional livirg
polymer by reaction with a halogen-containing compound having a polymerizable
moiety.
Most polymers, both natural and synthetic, are incompatible with
one another. This has become increasingly apparent as more and more polymers
having particularly good properties for special uses have become available,
and as efforts have been made to combine pairs of these polymers for the
purpose of incorporating the different, good properties of each polymer in~o
one product. More often than not, these efPorts have been unsuccessful
because the resulting blends have exhibited an instability, and in many cases~
the desirable properties of the two polymers were completely lost. Poly-
; ethylene is incompatible with polyisobutylene, for example, and a blend of
the two has poorer physica] properties than either of the homopolymers.
These failures were at first attributed to inadequate mixing procedures, but
eventually it was concluded that the failures were due simply to inberent ;~
incompatibilities. Although it is now believed that this is a correct ex-
planation~ the general nature of such incompatibility has remained somewhat
unclear, even to the present. Polarity seems to be a factor, i.e., two polar
polymers are more apt to be compatible than a polar polymer and a non-polar
polymer. Also, the two polymers must be structurally and compositionally
somewhat similar if they are to be compatible. Still further, a particular `;
pair of polymers may be compatible only within a certain range of relative
proportions of the two polymers; outside that range they are incompatible. `
Despite the general acceptance of the fact of incompatibility of
polymer pairs, there is much interest in devising means whereby the advan~a-
geous properties of combinations of polymers may be combined into one product. ~ ~;
.
, ~ :
' "'
10601'~0
One way in which this objective has been sought involves the
preparation of block or graft copolymers. In this way, two different poly-
meric segments, normally incompatible with one another, are joined together
chemically to give a sort of forced compatibility. Thus, the block or graft
copolymer in many instances possesses a combination of properties not normal-
ly found in a homopolymer or a random copolymer. ~ ;~
Resort to block copolymers or graft copolymers, however, has its ~ `
limitations in the case of block copolymers inasmuch as orly those monomers
can be used which are susceptible to anionic polymerization and this eliminates ;
a lot of potential polymeric segments. In the case of those graft copolymers ;~
previously availabole, they invariably are characterized by the presence of
substantial amount of homopolymer, either of the original homopolymer back-
bone or of the grafting monomer. To the extend that such homopolymer is
present, it serves not only as a diluent, but detracts materially from the
effectiveness of the desired properties which are sought to be built into ;
the graft copolymer.
Copending application Serial Number 135,095 discloses a process for
the preparation of graft copolymers having sidechains of predetermined mole-
cular weights, relatively free of homopolymers and which have novel combina-
-
tions of physical properties and such graft copolymers.
Such graft copolymers differ from those previously available in ;~
that the polymeric sidechains or macromolecular monomers 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 com- -~
polmd, and by selection of the appropriate terminating agent, a polymer
having a terminal polymer1zable group may be obtained. This polymer may
itself be further polymerized to form graft copolymers of the kind described
above. Alternatively, copolymeri3ation of this high molecular weight poly-
meri~able compound with a second compound, usually of relatively low molecular
- 2 -
0 `. ~
weight, also yields a grat copolymer o~ this type.
Accordingly the present invention provides a process for preparing
a copolymerizable macromolecuLar monomer comprising preparir~ a living polymer
by polymerizing at least one anionically polymerizable monomer in the presence
of an anionic polymerization initiator to thereby form a monofunctional
living polymer with a narrow molecular weight distribution, and thereafter
reacting the monofunctionaL living polymer with a ha:Logen-containing epoxide
or halogen-containing vinyl compound selected from the group consisting of -~
acrylyl chloride, methacrylyl chloride, vinyl haloalkyl ethers, vinyl esters
of haloalkanoic acids, allyl halides, methallyl halides, vinyl halides,
halomaleic anhydrides, halomaleate esters, and epihalohydrins. ~-
The present invention also provides a copolymerizable macromolecu- ~
lar monomer comprising a residue of an anionic initiator, polymerized units ;
of at least one anionically polymerizable monomer and a copolymerizable end ;;
group selected from the group consisting of :
R 0 Cl CH2
" ''' . '
O
-R3 - C - 0 - f = CH2 ~ ~
R4
. ~, .
-R3 - C = CH
14 ``~
/0\ ' ~,`~ '~,; ,`
-R3 - CH - CH2 `
'
O . .~ , .
- C - C = CH2
R4
~ 3 ~ -
, ;, .. .. . . . . .. . . . .
~LO~ 4~
- C CO : ;
Il \o : ~ :
R4 - C - CO / ~ ~
- C - CoOR
4 ~1 4 `~
R - C - COOR
'.' '~
OH OH
3 1 1 ~
-R - CH - CH2 -
C - COOH ;
R4 - C - COOH
wherein R3 is a valence bond or a lower alkylene radical and R4 is a hydrogen
or a lower alkyl radical, said macromolecular monomers having a molecular ~;
weight in the range of from 5,000 to SO,OOO and a narrow molecular weight
,:
distribution. ;
The preparation of such graft copolymers begins, as noted above,
with anionic polymerization of a copolymerizable macromolecular monomer. In
; .
most instances, such a copolymerizable macromolecular monomer is one having
an olefinic group although it may be an epoxy or thioepoxy group.
Those monomers susceptible to anionic polymerization are well known
and the present invention contemplates the use of all anionically polymeriz-
able monomers. Illustrative species include styrene, alpha-methyl styrene,
;~ acrylamide, N,N-lower alkyl acrylamides, N,N-dilower alkyl acrylamides,
acenaphthalene, 9-acrylcarbazole, acrylonitrile, methacrylonitrile, organic
isocyanates including lower alkyl, phenyl, lower alkyl phenyl and halophenyl
isocyana~es, organic diiocyanates including lower alkylene, phenylene and
tolylene diisocyanates, lower alkyl and allyl acrylates and methacrylates,
lower olefins, vinyl esters of aliphatic carboxylic acids such as vinyl
acetate, vinyl propionate, vinyl octoate, vinyl oleate and vinyl stearate~
~ 4 ~
::. - . . ~ . .
1C~6~
vinyl benzoate, vinyl lower alkyl ethers7 vinyl pyridines, isoprene, buta- ;
diene and lower alkylene oxides. The term "lower" is used above to denote ;
organic groups containing eight or fewer carbon atoms.
The catalyst for these anionic polymerizations is an alkali metal
alkyl, the alkyl being a lower alkyl, i.e., having eight or fewer carbon ~ ~?
atoms. The butyl lithiums are preferred particularly sec-butyl lithium ~ -~Lower alkyl lithiums and lower alkyl sodiumés are especially useful. Other
suitable catalysts include isopropyl lithium, ethyl sodium, n-propyl sodium,
n-butyl potassium, n-octyl potassium, n-butyl lithium, ethyl lithium, t-butyl
lithium and 2-ethylhexyl lithium. The alkali metal alkyls are either avail.
able commercially or may be prepared by known methods. Phenyl lithium, phenyl
sodium, etc. may also be used as a catalyst and they are likewise convenient-
ly available, by the reaction of bromo ben~ene and the appropriate alkali
metal.
The amount of catalyst is an important factor in anionic poly~
meri~ation because it determines the molecular weight of the living polymer.
If a small proportion of catalyst is used, with respect to the amount of ~ ~
;, ' ~; ;~;, :
monomer, the molecular weight of the living polymer will be larger than if ~ ;
a large proportion of catalyst is used. Generally, it is advisable to add ~`
catalyst dropwise to the monomer (when that is the selected order of addition) `~
until the persistence of the characteristic color of the organic anion, then ;
add the calculated amount of catalyst. The preliminary dropwise addition ~ ~
serves to destroy contaminants and thus permits better control of the poly- ;
merization.
The anionic polymerization must be carried out under carefully `~
controlled conditions, so as to exclude moisture and other contaminants. -~
The monomer and catalyst should be freshly purified and the apparatus in
which the polymerization is to be carried out should be carefully cleaned.
Techniqués~ for purifying the reactants and cleaning the reaction equipment
.. .. . . . .
-` 10~iL40
are well knol~n and need not be set forth here. The alkali metal catalyst
may be added to the monomer, or the monomer may be added to the catalyst.
A solvent generally is used to facilitate heat transfer and adequate mixing
of catalyst and monomer. The solvent should be inert. Hydrocarbons and
ethers are preferred, including benzene, toluene, dimethyl ether, diglyme, ;~
glyme, diethyl ether, tetrahyd~ofuran, N-hexane, cyclohexane and N-heptane.
The temperature of the polymerization will depend on the monomer. The poly-
merization of styrene is generally carried out at slightly abo~e room temper-
ature; the polymerization of alphamethyl styrene preferably is carried out at
-80C. The temperature of the anionic polymerization is not a critical fea-
ture of this invention.
The polymeric product is a so-called 'lliving polymer", i.e., it is
not terminated in the usual sense of that word as it is used in polymer
chemistry, but is susceptible of further reaction including further poly-
merization. The anionic polymerization is illustrated by the followir~ equa-
tion, where styrene is polymerized by sec-butyl lithium~
sec-BuLi ~ n CH2 - CH-~sec-Bu- CH2CH -CH2CH Li
n-1
If styrene is added to the above living polymer, the polymerization is re-
newed and the chain grows until no more monomeric styrene remains. ~lterna-
tively, if another different anionically polymerizable monomer is added, such
as butadiene, the above living polymer initiates the polymerization of the
butadiene and the ultimate living polymer which results consists of a poly-
styrene segment and a polybutadiene segment. The living polymer may be ter-
minated by reaction with a halogen-containing compound. Termination of the
above living polystyrene with methyl iodide is illustrated by the following
equation:
~014~
sec-Bu-CH2CH~ -CH27Hl Li ~ CH3I-~sec-Bu~ -CH2C~- CH2CHCH3 ~ LiI
~L~t L~10 ~
,;. ~...
Living polymers are characterized by relatively uriform molecular
weight, i.e., the distribution of molecular weights in an average living
polymer is quite narrow. This is in marked contrast to the typical polymer,
where the molecular weight distribution is quite wide.
An important feature of this invention is the uriformity of molecu-
lar weight of the living polymer which is prepared as the first step in the `~
overall synthesis ofthegraft~ copolymers of copending application serial
number 135,079. hs a result such graft copolymers have side chains of sub-
stantially uniform molecular weight. h particularly preferred embodiment of ; ~
this invention resides in living polymers or copolymerizable macromolecular ~ ;
monomers having an average molecular weight of from about 5,000 to about
50,000.
The living polymers herein are terminated by reation with a halogen- ;;;
contairing compound which also contains either a polymerizable olefinic group
or an epoxy or thioepoxy group. Suitable halogen-containing terminating 5,. ~. ' '
agents include vinyl halo alkyl ethers wherein the alkyl groups contains 9iX ` .
or fewer carbon atoms, vinyl esters of haloalkanoic acids wherein the -;
alkanoic acid contains six or fewer carbon atoms, allyl halides, epihalo~
~ .
~ 20 hydrins, acrylyl halides, methacrylyl halides, halomaleic anhydrides~ halo- ~ ;~
..
~ maleate esters, vinyl halides and halovinyl silanes. The halo group may be
- ,
chloro, fluoro, bromo or iodo; preferably~ it is chloro.
Termination of the living polymer by any of the above types of
terminating agents is accomplished simply by adding the terminating agent to
the solution of living polymer at the temperature at which the living polymer
is prepared. Reaction is immediate and the yield is theoretical. A slight
- 7 -
-: ,. ~ : : .. -: . . .. , : . ... .. . .
~ 60~
molar excess of the terminating agent, with respect to the amount of catalyst,
is used although the reaction proceeds on a mole-for-mole basis.
The following equations illustrate typical reactions in accordcance
with the practice of the present invention~
Living Polymer: R1 Rl ~: :
R CH2 - -R - - Cff2 CD ~ Li
Terminating ~n~
(a) X - R3 o _ C = CH2 ~ ~;
R4 :
(b) X - R3 C O - C CH
R4
,~'~ '.''
:10 (c) X - R3 C = CH2 `
R4
~0
(d) X - R - CH CH2
O ~;
(e) X - CC = CH2 ~: :
R4 .~
(f) X C - CO \ ~:.
Il O ., ~ .
~4 - C CO-" -
~Ig) X C - CooR4 ~ -~
R4 _ C CooR4
(h) X - R3 - CH - CH2 `
~,.0 '' .-
(i) X - C - C~ -
~0
- 8 -
- - - .
:. ': . '' :, - . , ~ :
Rl ¦ R~
(a)R--- CH2 C --CH2--C R3 OC - CH2
_ R2 R2 R4
,1 Rl O ~. ,
(b)R----CH - C ---CH2--- C -- R3 C----- OC = CH2
_ R2~ R2 R4
(c) n CH2_ ~3 CHz-- C--d3---C = C32
n R2 R4 . .
'' ' '; '
(d)1~ t C32 j CH2-- C-- R3_ C--C3
Rl RlO
(e) 1~ C112~OE12 l l 2
_ ,_ R~
(f) R~- CH2 C --CH ~ C -- C CO\ ::
l 111 ,~,
F~2 -n R2R4--C CO/ ~` ~
, , :
.
_ ~ _
1~ 0 ` ':
Rl¦ R-l
(g) R-- - CH2 C - ~ CH2 C - C - CoOR4
~ ~ n R2R4- C CoOR4
_ ;'~
(h) R I CH2 - C L CH2 - C - R3 - CH - CH
_ 12 R2
_ _ ~ .
Rl IRl OH OH
R ~~ CH2 IC - CH2 - C - R3 - CH - CH2
R2 R2 , .
n
Rl ¦ R~
~i) R - - CH2 - C- ~ CH2 - C - R3 - C - C~ H20
_ R2~ In R2 R4 - C - C~ ;
_ ,
_ p~l .
R - CH2 ~ IC _ CH2 - C - R3 - C - COOH
R2 R2
_ _ n R4 - C - COOH
,"', .~.
In the above equations, R, Rl, 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
aIkyl, such as sec-butyl; Rl will be either hydrogen or methyl; R2 will be ~ ¦
phenyl; and R4will be either hydrogen or lower alkyl radical.
In some instances, because of the nature of the living polymer and
1~6~14~
the monomer from which it :is prepared, or because of the nature of the ter-
minating agent, it is advisable to "cap" the living polymer with a reactant
such as a lower alkylene oxide, i.e.~ one having eight or fewer carbon atoms,
or &iphenyl 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 active hydrogens of a terminating agent. Thus, for example, `
acrylyl chloride while it acts as a terminating agent because of the presence
of the chlorine atom in its structure, also provides a carbonyl group in the
terminated polymer chain and this carbonyl group may provide a center for
attack by a second living polymer. The use of acrylyl chloride as a ter~
minating agent is much facilitated if the living polymer is first capped, ~ ; ;
then reacted with the acrylyl chloride. The resulting living polymer is a ``; ~;
substantially pure vinyl ester~ i.e., a living polymer which has been ter-
minated by a molecule of acrylyl chloride. If no capping agent is used in
this intermediate step, the resulting polymer either has twice the expected
~olecular 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 hydrogens of the acrylyl chloride. ~-
A particularly preferred terminating agent is ethylene oxide. It
20 reacts with the living polymer, with the destruction of its oxirane range as
follows: `
sec-2u-~ ~ 7CH ~
_ _ _ +
Li + C\2CH2--~sec-Bu GH~ - C ~U~C ~ 2
The above equation sho~s the reaction of ethylene oxide as a capping reagent
-- 11 --
:,
; . , , , . ~ .
~(~60~L40
with a living polymer prepared by the polymer:ization of styrene with sec-
bu~yl lithium.
The capping reaction is carried out quite simply, as in the case
of the terminating reaction, by adding the capping reactant to the living
polymer at polymeri~ation temperature. The reaction occurs immediately. As
in the case of the termination reactant, a slight molar excess of the capping
reactant with respect to the amount of catalyst, is used. The reaction ; ;~ ~-
occurs on a mole-for-mole basis.
When an epihalohydrin is used as the terminating reagent, the
resulting polymer contains a terminal epoxy group. This terminal epoxy
group may be converted to the corresponding glycol by warming with aqueous ~ ;
sodium hydroxide. The resulting glycol may be converted to a copolymer by
reaction with a high molecular weight dicarboxylic acid which may be prepared,
e.g., by the polymerization of a glycol or diamine with a molar excess of
phthalic anhydride, maleic anhydride, succinic anhydride, or the li~e. It --
may also be reacted with a diisocyanate to form a polyurethane. The diiso~
.,.. ;., .
cyana~!e may be e.g., the reaction product of a polyethylene glycol having an
average molecular weight of 400 with a molar excess of phenylene diisocyanate.
In another embodiment of the invention, an organic epoxide is co-
polymerized with a terminated living polymer containing an epoxy or thio-
epoxy end group. The graft copolymer which results is characterized by a
backbone having urinterrupted 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 ;~
fewer carbon atoms.
When a halomaleic arhydride or halomaleate ester is used as the
terminatir~ agent, the resultir~ polymer contains ester groups which may
be converted by hydrolysis to carboxyl groups. The resulting dlcarboxylic
-- 12 -- b
polymer may be copolymerized with glycols or diamines to form polyesters
and polyamides having a graft copolymer structure
It will be noted that the reaction of the living polymers herein
with the above terminatirg reagents yields products which, while they are not
living polymers, are themselves further polymerizable. Such further poly~
meri7ation may proceed either through the double bond or the glycol portion `~
or epoxy portion of the terminating reagent, so that the terminating reagent
thus acts as a Y in the formation of a graft copolymer. It will be noted
further that while the structure of the graft copolymers, of copending appli- ` `~-
cation serial rumber 135,079 conforms generally to that of the graft co-
polymers of the prior art, they are prepared in a notably different manner
than that of the prior art. Furthermore, they are significantly different,
structurally. Prior to the invention graft copolymers were prepared by
synthesizing a linear llbackbonel~ then grafting onto this backbone, growing
polymeric chains, and the ultimate result was a backbone having several
pendant polymeric chains. The graft copolymers of copending application ~;
serial number 135,079, on the other hand, may be prepared by first synthesiz-
ing these pendant polymeric chains (the living polymers or copolymerizable
macromolecular polymers~then polymerizirg the terminal portions of these
polymeric chains into a backbone. That is, the pendant chains, i.e.~ side-
chains, are syn-thesized first, then the backbone. The sidechains are thus
integral parts of the backbone. Obviously, although the two types of graft
copolymers resemble each other generally, they are different compositions, not
orly because they are prepared by significantly different processes3 but
because the pendant polymeric chains of the graft copolymers of this inven-
tion are of relatively uniform, minimum length, and are each an integral
part of the backbone, and because the backbone contains polymeric segments
of certain minimum length. These characteristics contribute materially to
the advantageous properties which inhere in such novel graft co;poly~lers.
: ~;
, . . . :
106~1~0
As noted earlier, the graf-t copolymers of the parent patent applica~
tion have unique properties and unique combinations of properties. These
unique properties and combinations of properties are made possible by the
novel copolymerizable macromolecular monomers herein which forces the com-
patibility of otherwise incompatible polymer segments. Thus~ the ad~antageous `-
properties of a polystyrene may be combined with the advantageous properties ;
~ .
of a polymethyl acrylate, although these two polymers normally are incompat-
. .~
ible with one another and mere physical mixtures of them have very little
strength and are not useful. To combine these advantageous properties in one
product, it is necessary that the different polymeric segments be present as ~ ;
relatively large segments. The properties of polystyrene do not become
apparent until the copolymerizable macromolecular polymer consists essentially
of at least about 20 recurring monomeric units. i.e., if a graft copolymer
comprising polystyrene segments is to be characterized by the advantageous
properties of polystyrene, then those polystyrene segments must~ individually,
consist essentially of at least about 20 recurring monomeric units. This
relationship between the physical properties of a polymeric segment and its
minimum size is applicable to the polymeric segments of all the copolymeriz- `~
able macromolecular monomers herein. In general, the minimum size of a
polymeric segment which is associated with the appearance of the physical
properties of that polymer in the graft copolymers is that which consists of
about 20 recurring monomeric units. Preferably, as noted earlier herein,
the polymeric segments, both of the copolymeric backbone and of the sidechains, ~-
will consist essentially of more than about 30 recurring monomer unit~
These polymeric segments may themselves be homopolymeric or they may be co-
polymeric.
The copolymerizable macromolecular monomers comprising polymeric
segments havir~ fewer than about 20 recurring monomeric units are~ neverthe-
less, useful for many applications, but preferably they have at least about
- 14 - ;
~6V14~
20 recurring monomeric units.
The invention is illustrated further by the following examples. In
each case, all materials should be pure and care should be taken to keep the ,~;
reactant mixtures dry and free of contaminants. All parts and percentages,
unless expressly stated to be otherwise, are by weight.
EXAMPLE 1
A solution of one drop of diphenyl ethylene at 40G. is treated
i:
portionwise with a 12% solution of t-butyl lithium in pentane until the
persistanoe of a light red color, at which point an additional 30 ml. (0.04
mole) of the t-butyl lithium solution is added, followed by 312 g. (3.0 `~
moles) of styrene. The temperature of the polymerization mixture is main-
tained at 40C. for 30 minutes whereupon the living polystyrene is terminated
by treatment with 8 ml. (0.08 mole) of vinyl-2-chloroethyl ether. The result-
ing polymer is precipitated by addition of the benzene solution to methanol
and the polymer is separated by filtration. Its number average molecular
.~ ,
weight, as determined by vapor phase osmometry, is 7,200 (theory: 7870)
i..
and the molecular weight distribution is very narrow, i.e., the Mw/Mn is less
~, : .-
than 1.06. ~ `
. .
EXAMPLE 2
Preparation of Polystyrene Terminated With Vinyl Chloroacetate
. ~
A solution of one drop of diphenyl ethylene in 2500 ml. of cyclo-
hexane at 40C. is treated portionwise with a 12% solution of sec-butyl
lithium in cyclohexane until the persistence of a light red color, at which
point an additional 18~ml. (0.024 mole) of the sec-buty1 lithium 1s added, ~`
followed by 312 g. (3.0 moles~ of styrene. The temperature of the poly- ~;~
merization mixture is maintained at 40C. for 30 minutes whereupon the living ;
polystyrene is capped by treatment with 8 ml. (0.040 mole? of diphenyl ethy-
lene, then terminated by treatment with 6 ml. (0.05 mole) of vinyl chloro-
acetate. The resulting polymer is precipitated by additian of -the cyclohexane
- 15 -
~'`' ~ .
~6~
solution to methanol and the polymer is separated by filtration. Itsnumber ~;
average molecular weight, as determined by vapor phase osmometry is 12,000
(theory: 13~265)~ and the molecular weight distribution is very narrow,
i.e., the Mw/Mn is less than 1~06~ ~
EX~MPLE 3 ~ -
Preparation of Polystyrene Terminated with Epichlorohydrin
A ben~ene solution of living polystyrene is prepared in Example 1
:: ,
and terminated by treatment with 10 g. (0.10 mole) of epichlorohydrin. The
resulting terminated polystyrene is precipitated with methanol and separated
by filtration. Its molecular weight, 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 Pol ~ ha-methyl styrene) Terminated ~ith
Vinyl Chloroacetate
A solution of 357 g. (3.0 moles)~of alpha-methyl styrene in 2500
ml. of 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 ml. (0.03 mole) of the t-butyl solution is added~ re- ~
sulting in the development of a bright red color. The temperature of the ~ :
mixture is 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-
tion. Itsnumber average molecular weight, as determined by vapor phase os-
mometry, is 14~280 ¦theory: 12~065) and the molecular weight distribution is
very narrow.
'
~ 16 ~
:;; ` , ~ . :
,, .
" '
. ~6V~4~
EXAMPLE 5 " ; `
Preparation of Poly(alpha-methyl styrene) Terminated w h ~ ;
Allyl Chloride
A solution of 472 g. (4.0 moles) of alpha-methyl styrene in 2,500
ml. of tetrahydrofuran is treated dropwise with a 12% solution of n-butyl `~
lithium in hexane until the persistence of a light red color. An additional
30 ml. of this n-butyl lithium solution is added resulting in the develop- ~ ~-
ment of a bright red color. The temperature of the mixture is then lowered
to -80C., and a~ter 30 minutes at this temperature 4.5 g. (0.06 mole) of
allyl chloride is added. The red color disappears almost immediately indi- `~
cating termination of the living polymer. The resulting colorless solution ~
is poured into methanol to precipitate the terminated poly(alpha-methyl ~ -
:. :
styrene) which is shown by vapor phase osmometry to have a number average
molecular weight of 11,000 (theory: 12,300).
PLE 6
Preparation of Polystyrene Terminated ~ith Methacrylyl ~;
Chloride ; ; ;
A solution of 0.2 ml of diphenyl ethylene in 2,500 ml. 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 ml. (0.031
mole) of this 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. is maintained throughout by external cooling and by controlling the
rate at which the styrene is added. This temperature is maintained for an
additional 30 minutes after all of the styrene has been added, and then i9
lowered to 20C. whereupon 4.4 g. (0.1 mole) of ethylene oxide is added,
causing the solution to become colorless. The living polystyrene :i9 terminated ;--
by reaction with 10 ml. (0.1 mole) of methacrylyl chloride. The resulting
polymer has a number average molecular weight, as shown by vapoF phase
- 17 -
~ , .
~6~
:
osmometry, of lO,000. ;~
Acrylyl chloride can be substituted for methacrylyl chloride in the
above procedure to give an acrylic acid ester end group on the polystyrene ~ ;
chain.
Examples 1-6 show the preparation of terminated living polymers. ;
These are used as starting materials in the procedures of Reference Examples
1-8 to prepare the graft copolymers herein. The terminated living polymers
appear as sidechains in the graft copolymers, with the polymerizable end
group of the terminated living polymer ending up as an integral part of the ~`
backbone of the graft copolymer.
REFERENCE EXAMPLE 1
Preparation of Graft Copolymer from Polystyrene Terminated
With Vinyl-2-Chloroethyl Ether and Ethyl Acrylate
To a solution of 18 g. of octylphenoxy polyethoxy ethanol (emulsi-
fier) in 300 g. of deionized water there is added, with vigorous agitation in `~
a Waring Blender, a solution of 30 g. of the polystyrene product of Example 1 ~-
and 70 g. of ethyl acrylate. The resultirg dispersion is purged with nitrogen,
then heated with stirring at 65C. whereupon 0.1 g. of ammonium persulfate is
added to initiate polymerization. Thereupon, 200 g. of ethyl acrylate and
O.S g. of 2% aqueous ammonium persulfate solution are added portionwise over
a period of three hours, the temperature being maintained throughout at 65C. `
The resulting graft copolymer emulsion is cast on a glass plate and allowed to
dry in air at room temperature to a flexible self-supporting film. The film
~, .
is shown to continue polystyrene segments by extraction with cyclohexane
which dissolves polystyrene; the cyclohexane extract on evaporation yields no
residue.
. ~
- 18 -
,,
., ,., , ., . .. ~ , . .
REFERENCE EXAMPLE 2
.
Preparation of Graf-t Copolymer of Poly(alpha-methyl styrene~
Terminated With Vinyl Ghloroacetate and Butyl _crylate
A solution of 50 g. of poly(alpha-methyl styrene) macromer termi-
nated with vinyl chloroacetate and having an average molecular weight of -
12,600 and 450 g. of butyl acrylate in 1,000 g. of toluene is purged with
nitrogen at 70C. then treated with 1 g. of azobisisobutyronitrile. The tem-
perature is maintained at 70C. for 24 hours to yield a solution of gra-ft
copolymer which is cast as a film on a glass plate. The dried film is slight-
ly tacky and is shown to contain polystyrene segments by extraction with
cyclohexane and evaporation of the cyclohexane extract, as above. ~-
REFERENCE EXAMPLE 3
Preparation of Graft Copolymer of Polystyrene Terminated With
Epichlorohydrin and Isobutylene
To a solution of 20 g. of polystyrene macromer terminated with
epichlorohydrin and having an average mol~cular weight of 10,000 in 1,000 ml.
of toluene at -70C., there is added 80 g. of isobutylene. 45 ml. of boron
trichloride ethyl ether complex is added slowly, the temperature being main-
tained at -70C. throughout. Polymerization occurs as the catalyst is added
and is complete almost immediately after all of the catalyst has been added.
The resulting graft copolymer is obtained by evaporating away the toluene and
washing the residual solid with methanol.
REFERENCE EXAMPLE 4
Preparation of Graft Copolymer of Polystyrene Terminated ~ith
Epichlorohydrin and Isobutylene
To 1,000 ml. of methyl chloride at -70C. there is added 10 g. of
polystyrene macromer terminated with epichlorohydrin, having an average
molecular weight of 10,000. To this resulting solution maintained at -70C.,
there is added concurrently and dropwise, a soltuion of 2 g. of aluminum
-- 19 -- ~: ~
.... . . .
4~ ` ~
chloride in 400 ml of methyl chloride and 90 g. of isobutylene. The time
required for these additions is one hour and at bhe end of this time poly~
merization is substantially complete. The resulting insoluble graft copolymer
is isolated by evaporation of the methylene chloride
REFERENCE EXAMPLE 5
~ ,.,
Preparation of Graft Copolymer of Pol~ etramethylene Ether
'
Diisocyanate and Polystyrene Macromer Terminated With .
Epichlorohydrin
Polytetramethylene ether diisocyanate is prepared by dissolving
290 g. of polytetramethylene ether glycol having an average molecular weight .-
of 2,900 in 600 ml. of tetrahydrofuran purging this solution with nitrogen
and then adding 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 reactants is capped and -~;
placed in a water bath at 50C. in which it is tumbled at about 30 rpm. ~-
After 8 hours, an additional 7.2 g. (0.025 mole) of the above liquid diiso~
cyanate is added and the reaction is continued for another 8 hours. At this ;
point, 4.35 g. (0.05 mole) of 2,4-tolylene diisocyanate is added and the ~;
polymerization is continued under the same conditions for another 8 hours. -
To a solution of 200 g. of polystyrene macromer terminated with
epichlorohydrin and having an average molecular weight of 12,000 in 100 ml.
of tetrahydrofuran and 100 ml. of water there is added dropwise a sufficiFnt
quantity of dilute sulfuric acid to adjust the pH to 2Ø The resulting
solution is stirred at 65C. for 8 hours resulting in complete hydrolysis of
the epoxide groups to glycol groups.
A mixture of a sol~tion of 60 g. of the above polytetramethylene ~;
ether diisocyanate in 60 ml~ of tetrahydrofuran, 60 g. of the above poly-
styrene glycol and 100 ml. of tetrahydrofuran is placed in a polymerization
bottle together with 0.6 g. of stannous octoate. The bottle is capped~
-- ~0 -- ::
., , -. :. : , . - : . . .~ , ,:
L4(1~
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 150C. and 20-30 psig. to a film the tensile strength of which is found
to be 1500 psig.
REFERENCE EXAMPLE 6
Preparation of Graft Copolymer of Polytetramethylene Ether -
Diisocyanate and Polystyrene Glycol
A reactor bottle containing a mixture of 87 g~ Of polytetramethyl~
ene ether glycol having an average molecular weight of 2,900 and 4.3 g.
(0.015 mole) of the liquid diisocyanate referred to in Example 11 is capped,
purged with nitrogen, and placed in a water bath at 65C. ~or 8 hours. The
resulting high molecular weight polyurethane glycol is cooled to room temper-
ature and 43 g. of polystyrene glycol (prepared as in Example 11) having an
average molecular weight of 8,600 and 350 ml. of tetrahydrofuran are added
and the bottle capped. After purging with nitrogen, 5.8 g. (0.023 mole) of
the above liquid diisocyanate is added and the bottle is rotated at 65C. for
8 hours. The resulting graft copolymer is isolated as a flexible, elastic
film by depositing it on a glass plate and air drying. Its tensile strength
is 1,000 psig.
REFERENCE EXAMPLE 7
~.
Preparation of Graft Co~olymer of Polystyrene Macromer
Terminated ~ith Methacrylyl Chloride and Eth~l Acrylate
A mixture of 21 g. of polystyrene macromer terminated with meth~
acrylyl chloride and having an average molecular weight of 10,000 prepared
as in Example 6. 28 g. of ethyl acrylate and 0.035 g. of azobisisobutyro~
ritrile is prepared at room temperature and kept for 18 hours~ under nitrogen,
at 67Co The resulting product is a tough, opalescent material which can be
molded at 160C. to give a clear, tough, transparent sheet.
- 21 -
.,. : . : . :
REFERENCE EXAMPLE 8
:. :
Preparation of Graft Copolymer from Pol~ alpha-methyl styrene)
Terminated With Allyl Chloride Macromer and Ethylene
A solution of 20 g. of poly~alpha-methyl styrene) macromer ter-
minated with allyl chloride and having an average molecular weight of 27,000
prepared as in Example 5 in 100 ml. of cyclohexane is prepared and treated ;~
with 5.5 ml. of 0.645 M diethyl aluminum chloride in hexane and 2 ml. of
vanadium oxytrichloride, then pressured with ethylene to 30 psig. This sys~
tem is agitated gently for about one hour at 30C. whereupon a polymeric
material precipitates from the solution. It is recovered by filtration and '
pressed into a thin transparent film which is to~lgh and flexible.
- 22
