Patent ID: 6248837
Filing Date: 2001-06-19
Classification: C08F,C08G

Abstract:
A process for preparing polyolefin diblock copolymer containing a transition metal prepared polyolefin segment and a free radical prepared polymer segment, which comprises the steps of:(a) contacting at least one C.sub.2 -C.sub.18 linear, branched or cyclic aliphatic or aromatic olefin under transition metal-catalyzed polymerization reaction conditions while in the presence of a borane dimer compound chain transfer agent and in the further presence of a transition metal catalyst/co-catalyst having a non-coordinated anion to form a borane-terminated polyolefin in situ by a B--H transformation reaction that occurs during a transition metal catalyzed olefin polymerization reaction;(b) oxidizing the borane group on the borane-terminated polyolefin formed in step (a) to convert the borane-terminated polyolefin to a stable free radical polymer capable of initiating free radical polymerization; and(c) adding at least one free radical polymerizable monomer to the reaction mixture from step (b) to initiate a living free radical polymerization reaction via said free radical polymer and to thereby form a polyolefin diblock copolymer comprising a polyolefin segment linked to a free radical polymerized segment via an ether linkage.