Reactive graft polymers

Abstract

Graft polymers are prepared by the free radical reaction of a base polymer such as polyethylene or polypropylene with an olefinic compound containing a tertiary alkyl ester group, which may be a simple carboxylic acid or a carbamic acid ester group. Upon melt blending or the like with polymers containing other functional groups, such as carboxy- or epoxy-functionalized polyphenylene ethers, the t-butyl groups are removed by thermal degradation and there are obtained copolymers which are useful to compatibilize blends of the corresponding polymeric constituents.

What is claimed is: .[.1. A graft polymer comprising molecules having: 
     
       n has an average value from 1 to about 5..]. .[.2.  A graft polymer according to claim 1 wherein the base chain is a polyethylene or polypropylene homopolymer chain..]. .[.3. A graft polymer according to claim 2 wherein the grafted moieties comprise up to about 5% by weight of the graft polymer..]. .[.4. A graft polymer according to claim 3 wherein the average value of n is about 1-2..]. .[.5. A graft polymer according to claim 4 wherein R 1  is hydrogen or methyl..]. .[.6. A graft polymer according to claim 5 wherein R 2  is t-butyl..]. .[.7. A graft polymer according to claim 6 wherein the base chain is a polyethylene chain..]. .[.8. A graft polymer according to claim 7 wherein the grafted moieties comprise about 2-3% by weight of the graft polymer..]. .[.9. A graft polymer according to claim 7 wherein the average value of n is about 1..]. .[.10. A graft polymer according to claim 7 wherein R 1  is hydrogen..]. .[.11. A graft polymer according to claim 7 wherein R 1   
     
     
        is methyl..]. .Iadd.12.  A graft polymer comprising molecules having: a base polymer chain which is a polyethylene or polypropylene homopolymer chain, and grafted moieties thereon having the formula ##STR8##.Iaddend. wherein:   R 1  is hydrogen, halogen, an alkyl radical containing about 1-4 carbon atoms or an aryl radical containing about 6-10 carbon atoms;   R 2  is a tertiary alkyl radical containing about 4-10 carbon atoms;   
     
     
       n has an average value from 1 to about 5.  .Iadd.13.  A graft polymer according to claim 12 wherein the grafted moieties comprise up to about 5% by weight of the graft polymer. .Iaddend. .Iadd.14. A graft polymer according to claim 13 wherein the average value of n is about 1-2. 
     
     
        .Iaddend. .Iadd.15.  A graft polymer according to claim 14 wherein R 1  is hydrogen. .Iaddend. .Iadd.16. A graft polymer according to claim 15 wherein R 2  is t-butyl. .Iaddend. .Iadd.17. A graft polymer according to claim 16 wherein the base chain is a polyethylene chain. .Iaddend. .Iadd.18. A graft polymer according to claim 17 wherein the grafted moieties comprise about 2-3% by weight of the graft polymer. .Iaddend. .Iadd.19. A graft polymer according to claim 17 wherein the average value of n is about 1. .Iaddend.