Grafted polymers having reactive groups at the base

The present invention provides grafted polymers that have pendent functional groups on the core of the polymer wherein the core is a polymerized alkylmethacrylate having a number average molecular weight from 500 to 1,000,000. The arms of the grafted polymer comprise anionically polymerized segments that have number average molecular weights from 1,000 to 300,000.

FIELD OF THE INVENTION 
This invention relates to polymers having polar groups. More particularly, 
the invention relates to highly branched or graft polymers having reactive 
groups. 
BACKGROUND OF THE INVENTION 
U.S. Pat. No. 4,503,188 describes the preparation of star-block polymers by 
reaction of anionically polymerized polymer segments with a multiester 
having the formula (CH.sub.2 .dbd.CH--CO--O--).sub.n --X wherein X is the 
residue of a polyhydroxyl compound having n hydroxyl groups, and n is from 
2 to 6. The anionically polymerized polymer segments such as a linear 
polybutadiene are essentially copolymerized with the unsaturation of the 
multiester to give a star structure having --CO--O-- groups at the core of 
the star polymer. 
U.S. Pat. No. 4,075,186 describes the preparation of branched polymers 
having from 25% to 75% by weight of a linear backbone of a polyacrylate 
following reaction of the polyacrylate with anionically polymerized 
polymer segments such as a linear polybutadiene. The polymer backbone has 
pendent --CO--OR groups that are partially consumed in the grafting 
reaction wherein R is a hydrocarbon radical having from 1 to 30 carbon 
atoms. The polyacrylate backbone has a minimum number average molecular 
weight of 10,000. 
SUMMARY OF THE INVENTION 
The present invention provides graft polymers that have pendent reactive 
groups that include esters (--CO--OR), anhydrides (--CO--O--CO--), amides 
(--CO--NRR'), imides (--CO--NR--CO--R'), nitriles (--CN), ketones 
(--CO--R), aldehydes (--CHO), acid halides (--CO--X), imines (--CNR), and 
halide groups on the core of the graft polymer wherein the core is a 
polymerized monomer containing reactive pendent groups having a number 
average molecular weight from 500 to 1,000,000. The arms of the graft 
polymer comprise anionically polymerized polymer segments that have number 
average molecular weights from 1,000 to 300,000. 
DESCRIPTION OF THE INVENTION 
The novel graft polymers of the invention are produced from linear base 
polymer segments by anionically polymerizing a conjugated alkadiene or an 
alkenyl aromatic compound to form a first polymer having terminal reactive 
groups and a peak molecular weight from 1,000 to 300,000, and reacting the 
first polymer with a second polymer having pendent reactive groups and a 
peak molecular weight from 500 to 1,000,000, wherein the pendent reactive 
groups are reactive with the terminal reactive groups on the first 
polymer. The resulting polymer retains some of the pendent reactive 
groups. 
The polymers of the invention are exemplified by the following structures: 
EQU (A--).sub.y --M (I) 
EQU (B--).sub.y --M (II) 
EQU (A--B--).sub.y --M (III) 
EQU (B--A--).sub.y M (IV) 
EQU (A--B--A--).sub.y --M (V) 
EQU (B--A--B--).sub.y --M (VI) 
EQU (A--).sub.y --M--(--B).sub.x (VII) 
EQU (A--B--).sub.y --M--(--B).sub.x (VIII) 
wherein each A is a homopolymer block or random copolymer block comprising 
predominantly polymerized alkenyl aromatic compounds, each B is a 
homopolymer block or random copolymer block comprising predominantly 
polymerized conjugated alkadienes, each M is a homopolymer, random 
copolymer, or block copolymer comprising pendent reactive groups such as 
esters (--CO--OR), anhydrides (--CO--O--CO--), amides (--CO--NRR'), imides 
(--CO--NR--CO--R'), nitriles (--CN), ketones (--CO--R), aldehydes (--CHO), 
acid halides (--CO--X), imines (--CNR), and halide groups. Both x and y 
are integers representing multiple arms in a graft/comb configuration, 
preferably from 5 to 1,000 arms per molecule. 
Other non-reactive comonomers may be copolymerized with the above monomers 
containing pendent reactive groups to form the M segment or block. 
Examples of non-reactive comonomers would be those defined as A and B and 
monomers such as ethylene, propylene, alpha-olefins and the like. 
The alkenyl aromatic compound employed as each A block or segment in 
structures I-VIII is a hydrocarbon compound of up to 18 carbon atoms 
having an alkenyl group of up to 6 carbon atoms attached to a ring carbon 
atom of an aromatic ring system of up to 2 aromatic rings. Such alkenyl 
aromatic compounds are illustrated by styrene, 2-butenylnaphthalene, 
4-t-butoxystyrene, 3-isopropenylbiphenyl, 4-vinylpyridiene, 
2-vinylpyridine and isopropenyl-napthalene. The preferred alkenyl aromatic 
compounds have an alkenyl group of up to 3 carbon atoms attached to a 
benzene ring as exemplified by styrene and styrene homologs such as 
styrene, .alpha.-methylstyrene, p-methylstyrene, and 
.alpha.,4-dimethylstyrene. Styrene and .alpha.-methylstyrene are 
particularly preferred alkenyl aromatic compounds, especially styrene. 
Each A block or segment in structures I-VIII is preferably at least 80% by 
weight polymerized alkenyl aromatic compound and is most preferably 
homopolymeric. 
Each B block or segment in structures I-VIII is preferably at least 90% by 
weight of one or more polymerized conjugated alkadienes. Most preferably, 
the B segments or blocks are homopolymeric. The conjugated alkadienes 
preferably have up to 8 carbon atoms. Illustrative of such conjugated 
alkadienes are 1,3-butadiene (butadiene), 2-methyl-1,3-butadiene 
(isoprene), 1,3-pentadiene (piperylene), 1,3-octadiene, and 
2-methyl-1,3-pentadiene. Preferred conjugated alkadienes are butadiene and 
isoprene, particularly isoprene. Within the preferred polyisoprene blocks 
or segments, the percentage of units produced by 1,4 polymerization is at 
least about 5% and preferably at least about 20%. 
Each M block or segment may be homopolymeric or a block or random copolymer 
containing at least one monomer that contains a reactive pendent group as 
defined above. 
Preferred monomers that contains reactive pendent groups include 
alkylmethacrylates and alkylmethacrylamides. 
The alkyl esters have the following structure: 
##STR1## 
wherein R.sub.1 is an alkyl, aryl or H group, R.sub.2 is an alkyl group 
comprising from 1 to 10 carbon atoms or H, R.sub.3 is an alkyl group 
comprising from 1 to 10 carbon atoms or H, and R.sub.4 is an alkyl group 
of 1-30 carbons or H. 
The preferred methacrylamides have the structure: 
##STR2## 
wherein R.sub.1 is an alkyl comprising from 1 to 15 carbon atoms or aryl 
and R.sub.2 is an alkyl comprising from 1 to 15 carbon atoms or aryl but 
not necessarily the same as R.sub.1. R.sub.3 is an alkyl, aryl or H group. 
The processes for producing the graft polymers of structures I-VIII involve 
conventional polymerization of the linear components followed by reaction 
of the linear components to form the graft polymer. Such procedures 
preferably include the production by anionic polymerization of a living 
polymer of each type of monomer before reaction of the polymer components. 
In each procedure to form an anionic polymer of structures I-VIII, the 
monomers are anionically polymerized in the presence of a metal alkyl 
initiator, preferably an alkali metal alkyl. The use of such initiators in 
anionic polymerizations is well known and conventional. A particularly 
preferred initiator is sec-butyllithium. 
The polymerization of the alkenyl aromatic compounds takes place in a 
non-polar hydrocarbon solvent such as cyclohexane or in mixed 
polar/non-polar solvents, e.g., mixtures of cyclohexane and an ether such 
as tetrahydrofuran or diethyl ether. Suitable reaction temperatures are 
from about 20.degree. C. to about 80.degree. C. and the reaction pressure 
is sufficient to maintain the mixture in the liquid phase. The resulting 
product includes a living poly(alkenyl aromatic compound) block having a 
terminal organometallic site which is used for further polymerization. 
The polymerization of the conjugated alkadiene takes place in a solvent 
selected to control the mode of polymerization. When the reaction solvent 
is non-polar, the desired degree of 1,4 polymerization takes place whereas 
the presence of polar material in a mixed solvent results in an increased 
proportion of 1,2 polymerization. Polymers resulting from about 6% to 
about 95% of 1,2 polymerization are of particular interest. In the case of 
1,4 polymerization, the presence of ethylenic unsaturation in the 
polymeric chain results in cis and trans configurations. Polymerization to 
give a cis configuration is predominant. 
The graft polymer is formed by mixing a solution of the living anionic 
polymer with a solution containing the polymer M which is the core for 
grafting of the anionic polymer. When the living anionic polymer ends with 
a B segment the grafting efficiency will be about 50-60%. When the living 
anionic polymer ends with an A segment the resulting graft will be about 
80-90+% efficient. Thus, the grafting efficiency may be controlled by use 
of A segment ends to increase the grafting efficiency of polymers that 
contain B segments. For example a living isoprene or butadiene homopolymer 
may be grafted at 80-90+% efficiency by adding or capping the living 
polymer with a minimal amount of A type monomer. Also suitable for this 
purpose would be monomers such as diphenylethylene which do not propagate 
well as a monomer but would be useable as an endcap to increase grafting 
efficiency. 
Polymerization of the methacrylate and methacrylamide monomers may be 
carried out by several different mechanisms that are well known in the art 
such as free radical polymerization, coordination polymerization by 
organometallic complexes (principally transition metal and lanthinide), 
coordination polymerization by metalloporphyrin complexes, and anionic 
polymerization. The preferable mechanisms are free radical and anionic 
polymerization. The most preferable is anionic polymerization. 
Polymerization of the methacrylate monomers takes place in either a 
non-polar solvent or a mixed solvent such as cyclohexane/ether, preferably 
in a non-polar solvent at a temperature from about -80.degree. C. to about 
100.degree. C., most preferably from about 10.degree. C. to about 
50.degree. C. 
The production of the polymers of structures VII and VIII requires mixing 
of different linear polymer arms prior to reaction with the 
alkylmethacrylate polymer segment. 
Each B segment or block has a molecular weight from 1,000 to 300,000 prior 
to any coupling. Each A block has a molecular weight from 1,000 to 300,000 
prior to any coupling. Each non-coupled M segment or block has a molecular 
weight from 500 to 1,000,000, preferably from 2,000 to 500,000 prior to 
reaction with the A and B blocks or segments. 
The graft polymers are produced by reacting the living anionic block 
polymers (composed of A and/or B, etc.) with the M blocks or segments at a 
temperature between -10.degree. C. and 100.degree. C. for at least 2 
minutes. 
In a further modification of the graft polymers of Structures I-VIII used 
in the invention, the graft polymers are selectively hydrogenated to 
reduce the extent of unsaturation in the aliphatic portion of the polymer 
without substantially reducing the aromatic carbon-carbon unsaturation of 
any aromatic portion of the block copolymer. However, in some cases 
hydrogenation of the aromatic ring is desired. Thus, a less selective 
catalyst will work. 
A number of catalysts, particularly transition metal catalysts, are capable 
of selectively hydrogenating the aliphatic unsaturation of a copolymer of 
an alkenyl aromatic compound and a conjugated alkadiene, but the presence 
of the M segment or block can make the selective hydrogenation more 
difficult. To selectively hydrogenate the aliphatic unsaturation it is 
preferred to employ a soluble colloidal catalyst formed from a soluble 
nickel compound and a trialkylaluminum. Nickel naphthenate or nickel 
octoate is a preferred nickel salt. This catalyst system is one of the 
catalysts conventionally employed for selective hydrogenation absent alkyl 
methacrylate blocks. 
In the selective hydrogenation process, the base polymer is reacted in 
situ, or if isolated is dissolved in a suitable solvent such as 
cyclohexane or a cyclohexane-ether mixture and the resulting solution is 
contacted with hydrogen gas in the presence of the nickel catalyst. 
Hydrogenation takes place at temperatures from about 25.degree. C. to 
about 150.degree. C. and hydrogen pressures from about 15 psig to about 
1000 psig. Hydrogenation is considered to be complete when at least about 
90%, preferably at least 98%, of the carbon-carbon unsaturation of the 
aliphatic portion of the base polymer has been saturated, as can be 
determined by nuclear magnetic resonance spectroscopy. Under the 
conditions of the selective hydrogenation no more than about 5% and 
preferably even fewer of the units of the A blocks will have undergone 
reaction with the hydrogen. The selectively hydrogenated block polymer is 
recovered by conventional procedures such as washing with aqueous acid to 
remove catalyst residues and removal of the solvent and other volatiles by 
evaporation or distillation. 
For polymers of the invention having adjacent (1-methyl-1-alkyl)alkyl ester 
groups, the ester groups convert to stable anhydride rings having six 
members after heating of the polymer to a temperature in excess of 
180.degree. C. as described in U.S. Pat. No. 5,218,053 which is 
incorporated by reference herein. Thermal conversion to anhydride rings 
likely occurs during reaction of the ester groups with primary or 
secondary amines facilitating the conversion reactions described in column 
3, lines 32-62, of U.S. Pat. No. 4,246,374 which disclosure is 
incorporated by reference herein. 
The graft block polymers of the invention will contain pendent reactive 
groups that did not react with the living anionic graft segments and have 
utilities conventional for such polymers. The polar polymers are 
particularly useful as viscosity modifying agent for motor oils, greases 
and gear/transmission fluids and in blends with engineering 
thermoplastics, asphalt compositions, adhesive formulations, including 
laminating adhesives for flexible packaging, sealants, fibers, and 
coatings formulations, especially coatings based on water emulsions. 
Examples of useful products include adhesives for tapes, labels, decals, 
and mastics. The polymers of the invention demonstrate significantly 
improved resistance to atmospheric hydrolysis in comparison to maleic 
anhydride modified polymers which have some of the same utilities.

Example 1 Poly(styrene)-Poly(t-butylmethacrylate) Graft Polymer 
This example is illustrative of a bench-scale synthesis, however the 
reaction conditions (i.e. solvents, temperatures and reaction times) are 
very similar to procedures used for pilot plant runs. 
A 2 liter glass reactor was charged with 1092 grams of anhydrous 
cyclohexane, 70 grams of anhydrous diethyl ether and 100 grams of styrene 
monomer that had been purified over alumina. The reaction mixture was 
heated to 45.degree. C. and then pre-titrated with s-BuLi to remove protic 
impurities. In this particular run, 0.4 ml of 1.44M s-BuLi was required to 
titrate the reaction mixture. The theoretical charge of s-BuLi, 9.0 ml, 
was then added to initiate the polymerization of the styrene block. The 
styrene was allowed to react for 30 minutes. 
A second reaction mixture was prepared wherein 98.6 grams of TBMA (purified 
by passing the monomer over 13X molecular sieves, then alumina) was added 
slowly instead of the styrene. The TBMA polymerization was allowed to 
continue for 15 minutes. 
The poly(TBMA) and polystyrene were then reacted at room temperature for 
about one hour to permit reaction of the terminal lithium groups on the 
polystyryllithium with the ester groups on the poly(TBMA). The polymer was 
then precipitated in methanol, and then dried to a constant weight in a 
vacuum oven. 
Example 2-Poly(styrene-1,3-butadiene)-g-P(TBMA) Graft Polymers 
Using the same basic experimental procedure described in Example 1, 
1,3-butadiene was added to the first reaction mixture after polymerization 
of the styrene. The reagents used are as follows: 
Cyclohexane, 1500 ml 
Diethylether, 70 g 
1,3-butadiene, 96 g 
s-BuLi (1.44M), 6.67 ml 
TBMA, 19 g 
The BD block was allowed to polymerize for 45 min at 45.degree. C. The 
polymerized TBMA was added, and the coupling reaction was allowed to 
proceed before termination with methanol. 
GPC analysis showed a single peak with a peak molecular weight of 
approximately 16,000 g/mol. NMR confirmed the composition. 
Example 3-Polybutylmethacrylate Grafted With Polystyrene 
All reactions were carried out in a glove box to provide an inert 
atmosphere. 
A 600 ml beaker was charged with 380 ml of cyclohexane, 20 ml of 
diethylether and 2-3 drops of diphenylethylene (titration indicator). The 
solution was titrated with sec-butyllithium to a light orange end point. 
Then 3 ml of 1.4M sec-butyllithium was added to the solution, followed by 
55 ml of styrene monomer. The solution became dark orange and was allowed 
to polymerize for 20 minutes. Then a solution of a 50,000 g/mole (styrene 
e.g. by GPC) polybutylmethacrylate, dissolved in 30 ml of cyclohexane and 
5 ml of diethyl ether, was added to the living polystyrene solution. (The 
polybutylmethacrylate was titrated with sec-butyllithium and 
diphenylethylene prior to adding it to the polystyrene). The viscosity 
increased immediately and the solution color faded to a light yellow. The 
reaction was stirred for 20 minutes and terminated with methanol. The 
reaction product was precipitated in methanol and dried under vacuum. This 
procedure was also used to graft polystyrene to an 
isobutylmethacrylate/methylacrylate copolymer and to an 
isobutylmethacrylate/t-butylmethacrylate copolymer. Gel Permeation 
Chromatography (GPC) analysis of these polymers indicated that the 
products are 80-90+% grafted. 
Example 4-Polybutylmethacrylate Grafted With Polyisoprene 
A 1 liter beaker was charged with 380 ml of cyclohexane, 20 ml of 
diethylether and 2-3 drops of diphenylethylene. The solution was titrated 
with sec-butyllithium to a light orange end point. Then 3 ml of 
sec-butyllithium was added and 100 ml of isoprene monomer was added in 
several portions and allowed to stir for 40 minutes after the last 
isoprene addition. A solution of 15.4 g of polybutylmethacrylate dissolved 
in cyclohexane and diethyl ether was titrated with sec-butyllithium and 
added to the living polyisoprene solution. There was an immediate increase 
in solution viscosity as the color turned yellow. The reaction was allowed 
to stir for 30 minutes and was then terminated with methanol. The product 
was precipitated into methanol and dried in a vacuum. 
Similar results were obtained when the diethylether was replaced with 
diglyme and ortho-dimethoxybenzene as modifiers. 
This procedure was also used to graft polyisoprene to 
isobutylmethacrylate/methylmethacrylate copolymers and to 
isobutylmethacrylate/t-butylmethacrylate copolymers. GPC analysis of the 
products indicated that they were 50-60% grafted. 
Example 5-Anionically Polymerized Polybutylmethacrylate 
In a glove box, a 1 liter polymerization bottle was charged with 315 ml of 
cyclohexane, 35 ml of diethyl ether and 2-3 drops of diphenylethylene. The 
solution was titrated with sec-butyllithium to a light orange end point. 
Then 1.5 ml of diphenyl ethylene was added and 5 ml of 1.4 m 
sec-butyllithium was reacted with it for 20 minutes. The bottle was then 
closed with a septum cap and removed to an ice water bath and nitrogen 
manifold. Then 39.15 ml of butylmethacrylate was added as quickly as 
possible and allowed to react for 2 minutes after the last monomer 
addition. The reaction was terminated with methanol at 0.degree. C. 
precipitated into methanol and dried in a vacuum oven. 
This procedure was used to prepare other polymethacrylate polymers for 
grafting as follows: 
1) 80% iso-butyl methacrylate/20% methylmethacrylate 
2) 60% iso-butyl methacrylate/40% methylmethacrylate, and 
3) 50% iso-butyl methacrylate/50% tert-butylmethacrylate. 
Example 6-S-I Diblock Grafted to Polyisobutyl Methacrylate 
A 1 liter beaker was charged with 650 ml of cyclohexane and 2-3 drops of 
diphenylethylene. The solution was titrated with sec-butyllithium to a 
light yellow end point. Then 1.25 ml of 1.4 m sec-butyllithium was added 
followed by 21 ml of styrene monomer and allowed to react for 30 minutes. 
Then 103 ml of isoprene was added in 3 portions and allowed to stir for 1 
hour after the last addition. Then 12 ml of a 10 wt% 
polyisobutylmethacrylate solution (in cyclohexane) was added. The solution 
viscosity increased immediately and the reaction stirred for 1 hour. The 
reaction was terminated with methanol. The product was precipitated in 
methanol and dried in a vacuum oven. 
This procedure was also used to prepare a graft copolymer of the 
polystyrene/polyisoprene diblock polymer to an 
isobutylmethacrylate/methylmethacrylate copolymer and to an 
isobutylmethacrylate/methylmethacrylate copolymer. GPC analysis showed the 
products to be 50-60% grafted. 
Example 7-Poly(isoprene)-g-Poly(n-butylmethacrylate) 
A free-radically prepared methacrylate polymer was purchased for use as the 
core segment as described below. The methacrylate polymers were washed 
with methanol and dried in a vacuum oven prior to use. The polymers were 
then dissolved in either cyclohexane or a mixture of cyclohexane and 
diethylether, and stored over 13X molecular sieves. Gel-permeation 
chromatography (GPC) was used to analyze the reaction products. 
In a glove box purged with nitrogen, a 400 ml beaker was charged with 180 
ml of cyclohexane and 20 ml of diethylether. The solution was titrated to 
dryness using 2-3 drops of diphenylethylene and adding sec-BuLi until the 
solution became yellow/orange in color. The target amount of 1.25 ml of 
1.4M sec-BuLi was added followed by 29 ml of isoprene. After a 1 hr 
reaction time; 100 ml of the living polymer solution was transferred into 
a clean 150 ml beaker and 10 ml of a poly-n-butylmethacrylate solution 
(the solution was prepared from 10 grams of polymer dissolved into an 
80/20 cyclohexane and diethylether mixture to make 100 ml of total 
solution). The reaction was allowed to stir for 30 minutes and was 
terminated with methanol. GPC showed a shift in molecular weight from 155K 
for the PMA to 1053K for the graft polymer (molecular weights are given in 
styrene equivalents). Grafting was approximately 50-60% based on GPC data. 
Example 8 -Poly(Styrene-b-Isoprene)-g-Poly(n-Butylmethacrylate) and 
Poly(Styrene-b-Isoprene)-g-Poly((C.sub.10 -C.sub.20)-methacrylate) 
Starting with a commercial methacrylate polymers as described in Example 7, 
a 400 ml beaker was charged with 180 ml of dry cyclohexane, 20 ml of dry 
diethylether and 2-3 drops of DPE. The solution was titrated with 
sec-butyllithium to an orange/yellow color and then 1.25 ml of 1.4M 
sec-butyllithium was added. Next, 20 ml of styrene monomer was added and 
allowed to polymerize for 30 minutes. Then 30 ml of isoprene monomer was 
added and allowed to polymerize for 90 minutes. Then 10 ml of the 
n-butylmethacrylate solution (10 grams in 100 ml of cyclohexane/ether 
solution) was added and reacted for thirty minutes. The reaction was 
terminated with methanol. A second anionic polymerization was performed as 
above and this time 10 ml of poly-(C.sub.10 -C.sub.20)-methacrylate 
solution (10 grams of polymer dissolved in cyclohexane to make 100 ml of 
solution) was added and reacted for 30 minutes. The reaction was 
terminated with methanol. Both reaction products were analyzed by GPC and 
found to have grafted onto the methacrylate polymers. Grafting was 
approximately 50-60%, based on GPC data. 
Example 9-(Poly-Styrene-b-Isoprene)-g-Poly-(C.sub.10 
-C.sub.20)-methacrylate-g-(Poly-Isoprene) 
Starting with a commercial methacrylate polymer as described in Example 7, 
a 400 ml beaker was charged with 180 ml of cyclohexane, 20 ml of 
diethylether and 2-3 drops of DPE. The solution was titrated with 
sec-butyllithium to an orange/yellow color. Next, 1 ml of 1.4M 
sec-butyllithium was added and 15.5 ml of styrene monomer was added and 
reacted for 30 minutes. Then, 1 ml of 1.4M n-butyllithium was added and 20 
ml of isoprene was added and reacted for 30 minutes. Two more 20 ml 
additions of isoprene monomer were made and reacted as above. Finally, 10 
ml of the poly-(C.sub.10 -C.sub.20)-methacrylate solution (10 grams of 
polymer dissolved in cyclohexane to make 100 ml of solution) was added and 
reacted for 30 minutes. The reaction was terminated with methanol. Both 
reaction products were analyzed by GPC and found to have grafted onto the 
methacrylate polymers. Grafting was approximately 50-60%, based on GPC 
data. 
Example 10-Poly(Styrene)-g-Poly(n-Butylmethacrylate) 
Starting with a commercial methacrylate polymer as described in Example 7, 
a 400 ml beaker was charged with 110 ml of a 90% cyclohexane/10% 
diethylether solution and 2-3 drops of DPE. The solution was titrated with 
sec-butyllithium to an orange/yellow color. Then 1.25 ml of 1.4M 
sec-butyllithium was added and 19.25 ml of styrene was added and 
polymerized for 30 minutes. Then 30 ml of n-butylmethacrylate solution 
(the solution was prepared from 10 grams of polymer dissolved into an 
80/20 cyclohexane and diethylether mixture to make 100 ml of total 
solution) was added and reacted for 30 minutes. GPC analysis showed that 
the product was 80% grafted. 
Example 11 Poly(styrene-1,3-butadiene)-g-P(TBMA) 
The basic experimental setup described in Example 1 was used here. The 
following reagents were used: 
cyclohexane, 150 g 
diethylether, 14.0 ml 
s-BuLi, 0.40 ml 
styrene, 6.4 ml 
1,3-butadiene, 28 ml 
P(TBMA) as a 6 wt% solution in cyclohexane/diethylether The polymerized 
t-butyl methacrylate (P(TBMA)) was anionically polymerized by s-BuLi at 
about 25.degree. C. in cyclohexane and 6 wt% diethylether. The P(TBMA) 
polymerization was not terminated prior to mixing with the 
poly(styrene-1,3-butadiene)-Li diblock. GPC analysis of an aliquot of 
P(TBMA) showed the number average molecular weight to be 10,500 with a 
molecular weight distribution of 1.37. The living 
poly(styrene-1,3-butadiene)-Li diblock was polymerized by first initiating 
the styrene block and allowing it to react for 30 minutes at 45.degree. C. 
Then 1,3-butadiene was added and allowed to react for an additional 30 
minutes. An aliquot of the poly(styrene-1,3-butadiene) diblock was taken 
from the reactor and terminated with methanol. The GPC analysis for the 
diblock revealed a Mn of 40,000 (target was styrene block of 10,000 and 
1,3-butadiene of 30,000). Inside a dry box, the P(TBMA) and the 
poly(styrene-1,3-butadiene)-Li were both quickly poured together into a 
third vessel and allowed to react for 2 hours. The grafting efficiency was 
estimated to be 45% by GPC peak areas. The product was precipitated in 
methanol and redissolved in THF to produce tensile bar samples and samples 
for dynamic thermal mechanical analysis. 
The final product was a white rubbery solid that had significant tensile 
strength. The average tensile strength of three bars was determined to be 
1780 psi. The poly(styrene-1,3-butadiene) diblock control had a tensile 
strength of 40-50 psi. The higher strength of the graft block copolymer 
demonstrates that useful and novel thermoplastic elastomers can be 
prepared with the present invention. Moreover, the DMTA revealed a curve 
typical for a well phase separated block copolymer that had two glass 
transition temperatures, -60.degree. C. for the butadiene phase and 
+105.degree. C. for the styrene/TBMA phase.