RADICAL POLYMERIZATION KINETICS OF POLY(ETHYLENE OXIDE) MACROMONOMERS

Radical polymerization of poly(ethylene oxide) macromonomers carrying a methoxy group on the one end and a p-vinylbenzyl or a (p-vinylphenyl )butyl group on the other end was investigated in benzene and water. T he overall rate of polymerization was found to be more than 50 times h igher in water than that in benzene. Apparent rate constants of propag ation and termination were evaluated based on ESR measurements under i rradiation, while initiator efficiency was estimated from inhibition p eriod measurements. Very rapid polymerization in water was then reason ably attributed to a combined result of locally concentrated propagati ng radicals and monomers in their micellar organization, together with high initiator efficiency, enhanced rate of propagation, and reduced rate of termination there.