Patent ID: 6046273
Filing Date: 2000-04-04
Classification: C08F,C08L

Abstract:
A process for improving the thermal stability of alpha-substituted acrylic acid ester graft copolymers comprising:(a) making a graft copolymers comprising a backbone of a propylene polymer material having graft polymerized thereto monomers consisting of (i) an ester of a 1-3 C alkyl-substituted acrylic acid and (ii) a 1-3 C alkyl-substituted acrylic acid as the only comonomer, wherein the total amount of polymerized monomers is about 20 to about 240 parts per hundred parts of the propylene polymer material and the amount of (ii) is about 1% to about 20%, based on the total weight of the monomers, whereby 1% weight loss of the graft copolymer by TGA occurs at a temperature of not less than 290.degree. C., and(b) removing any unreacted grafting monomer from the resulting grafted propylene polymer material, decomposing any unreacted initiator, and deactivating any residual free radicals in the material.