Patent ID: 7632891

Claim:
A process for the preparation of a grafted thermoplastic or elastomeric polymer or copolymer, which process comprises in a first step A) the preparation of a nitroxyl terminated oligomer or polymer by controlled free radical polymerization of an ethylenically unsaturated monomer or monomer mixture a1) in the presence of a nitroxyl ether containing a structural element of formula (Ia), wherein X is selected such, that cleavage of the O—X bond occurs and a radical X• is formed capable of initiating polymerization; or a2) in the presence of a nitroxyl radical containing a structural element of formula (Ib) and a free radical initiator capable of initiating polymerization; where unreacted monomer or monomers are removed and the nitroxyl terminated oligomer or polymer is isolated, and in a second step B) heating, mixing and reacting the nitroxyl terminated oligomer or polymer of step A) together with a thermoplastic or elastomeric polymer or copolymer at a temperature of between 150° C. and 300° C., wherein the structural elements of formula (Ia) and (Ib) are wherein G 1 , G 2 , G 3 , G 4 are independently C 1 -C 6 alkyl or G 1 and G 2 or G 3 and G 4 , or G 1 and G 2 and G 3 and G 4 together form a C 5 -C 12 cycloalkyl group; and G 5 , G 6 independently are H, C 1 -C 18 alkyl, phenyl, naphthyl or a group COOC 1 -C 18 alkyl, where X is selected from the group consisting of R 20 is hydrogen or C 1 -C 12 alkyl; the alkyl groups are unsubstituted or substituted with one or more —OH, —COOH or —C(O)R 20 groups; and the aryl groups are phenyl or naphthyl which are unsubstituted or substituted with C 1 -C 12 alkyl, halogen, C 1 -C 12 alkoxy, C 1 -C 12 alkylcarbonyl, OH, —COOH or —COO(C 1 -C 12 )alkyl and where the thermoplastic or elastomeric polymer or copolymer is selected from the group consisting of low density polyethylene, high density polyethylene, polyproylene, polystyrene, styrene-block copolymers, ethylene-propylene-diene modified rubber, ethylene propylene rubber, polybutylene, polyisobutylene and poly-4-methylpentene-1.