Olefin graft copolymers prepared using borane-containing olefin backbone polymers

Claim 1

A process for preparing a graft copolymer having the formula I ##STR9## wherein R 1 and R 2 are the same or different and are selected from H, C 1 to C 20 linear or branched alkyl, phenyl and alkyl substituted phenyl; R 3 is a direct linkage or a divalent linear or branched hydrocarbon having from 1 to 20 carbon atoms; W is a polar substituent; M is the residue of a free radically polymerizable monomer; n and p are the same or different and are the degree of polymerization of M ranging from 1 to about 70,000; (M) n and (M) p comprise polymer segments chemically bonded as side chains or chain ends; x ranges from about 50 to about 70,000; (a) ranges from 0 to 20,000; (b) ranges from 1 to about 20,000; (c) ranges from 0 to about 20,000; and the sum of (b)+(c) ranges from at least 1 to about 20,000, which comprises: (i) contacting in the presence of a Ziegler-Natta polymerization catalyst a mixture of at least one C 2 to C 22 alpha-monoolefin and a borane-containing monomer having the structure CH 2 ═CH(CH 2 ) m --BR 4 R 5 , wherein m is an integer ranging from 3 to 12 and R 4 and R 5 are the same or different and are selected from the group consisting of C 1 to C 10 alkyl groups and C to C 10 cycloalkyl groups; (ii) subjecting the mixture from step (i) to polymerization conditions to form a copolymer product containing borane units; (iii) contacting the copolymer of step (ii) with at least one free radically polymerizable monomer in the presence of a free radical catalyst capable of converting said borane units into free radicals; and (iv) subjecting the mixture of step (iii) to free radical polymerization conditions to convert at least a portion of said borane units to free radicals and to thereby initiate graft polymerization and the formation of a graft copolymer product containing polymeric side chains based on said free radically polymerizable monomer.