Styrene polymerization with some new macro or macromonomeric azoinitiators having peg units

Abstract

Abstract Several new macroinitiators and macromerinitiators (macroinimers) were synthesized and evaluated for the bulk polymerization of sytrene at 60°C. Macroinitiators were prepared from the reaction of 4,4′‐dicyano‐4,4′ azovaleryl chloride ( 1 ) with poly(ethylene glycol) (PEG) with a M ω of 400 and with either benzoyl chloride, acetyl chloride, phenyl isocyanate, or poly(ethylene glycol) oleyl ether. Macromer initiators were also prepared from the reaction of 1 with PEG having M ω values of 200, 400, 600, 1000, or 1500 and with 4‐vinylbenzyl chloride. The bulk polymerization of styrene by macroinimers gave crosslinked styrene‐PEG block copolymers, while the polymerization by macroinitiators gave soluble copolymers. The molecular weights of the styrene‐PEG block copolymers obtained with macroinitiators having either oleyl, benzoyl, or phenyl urethane end groups were 22000–29000 g/mol. DSC measurements showed that the crosslinked block copolymers had crystalline PEG units with melting transitions ranging from 11–37°C. © 1994 John Wiley & Sons, Inc.