SYNTHESIS OF CONTROLLED BLOCK AND GRAFT-COPOLYMERS .1. BLOCK POLYMERIZATIONS INITIATED ASYMMETRIC TELECHELIC BROMO-TERMINATED POLYMER TOGETHER WITH MANGANESE CARBONYL

Various types of halogen-terminated polymers having different backbones were synthesized and used as polymeric initiators together with manganese carbonyl for block polymerizations. The number of end groups and the molecular weights of the polymeric initiators could be varied by adjusting the feed composition and the transfer agent. Block polymerizations of methyl methacrylate and styrene with these telechelic bromo-terminated polymers-manganese carbonyl initiator systems were carried out photochemically at 30 degree C and in the dark at 80 degree C. It was found that the dark polymerization with the initiator system at 80 degree C provided excellent conditions to control the length of the blocks.