Abstract: A graft copolymer containing anhydride groups is made by (1) making a graft copolymer comprising a backbone of a propylene polymer material having graft polymerized thereto polymerized monomers selected from the group consisting of (a) at least one acrylic acid substituted with a 1-3 C alkyl group and (b) a mixture of at least one of these substituted acrylic acids and a vinyl compound capable of copolymerizing therewith, wherein the total amount of polymerized monomers is about 20 parts to about 240 parts per hundred parts of the propylene polymer material and the amount of the substituted acrylic acid is 60 mole % or more of the polymerized monomers, and (2) heating the graft copolymer to a temperature of about 170.degree. C. to about 300.degree. C. to dehydrate the acid groups in the graft copolymer to form anhydride groups.

Abstract: The thermal stability of alpha-substituted acrylate graft copolymers can be improved by (a) making a graft copolymer comprising a backbone of a propylene polymer material having graft polymerized thereto monomers comprising (i) a 1-3 C alkyl-substituted acrylic acid and (ii) an ester of a 1-3 C alkyl-substituted acrylic acid, 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 (i) is about 1 to about 20%, based on the total weight of monomers, 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.

Abstract: A graft copolymer of a propylene polymer material is prepared by (1) making an oxidized propylene polymer material by (a) irradiating a porous particulate propylene polymer material in the substantial absence of oxygen, (b) exposing the irradiated propylene polymer material to a controlled amount of oxygen of greater than 0.004% but less than 15% by volume at a temperature of 40.degree. C. to 110.degree. C., and (c) heating the irradiated polymer material to a temperature of at least 110.degree. C. in the presence of a controlled amount of oxygen within the same range as is used in the previous step, (2) dispersing the resulting oxidized propylene polymer material in water in the presence of a surfactant at a temperature of 30.degree. C.-90.degree. C., (3) adding (a) a primary reducing agent, (b) a chelating agent, and (c) a secondary reducing agent, (4) adding at least one vinyl monomer, and (5) recovering the graft copolymer from the reaction mixture.

Abstract: Disclosed are certain 1,3-2,4-di(substituted arylidene)-and 1,3-2,4-di(substituted heteroarylidene)-D-sorbitols which are useful as clarifying and nucleating additives for crystalline and semi-crystalline polyolefin compositions. Also disclosed are such poly(C.sub.1 -C.sub.8 alpha olefin) compositions containing them.

Abstract: Disclosed are certain 1,3-2,4-di(substituted arylidene)- and 1,3-2,4-di(substituted heteroarylidene)-D-sorbitols which are useful as clarifying and nucleating additives for crystalline and semi-crystalline polyolefin compositions. Also disclosed are such poly(C.sub.1 -C.sub.8 alpha olefin) compositions containing them.