High molecular weight poly(alpha-methylstyrene) formed by free radical polymerization in emulsions

Free radical polymerizations of ol-methylstyrene (AMS) were performed in di spersions of oil in water using a mixture of nonionic nonylphenoxy poly(eth ylene glycol) surfactants and initiated with ascorbic acid/hydrogen peroxid e at temperatures ranging from 3 to 45 degreesC. A bimodal distribution of high (similar to 60,000 g/mol) and low molecular weight components (similar to 8000 g/mol) was analyzed by size-exclusion chromatography (SEC). The re lative amount of the low molecular weight fraction increased with increasin g the polymerization temperature. The polymer yields decreased from 52% at 3 degreesC to 3% at 45 degreesC. The syndiotactic content of PAMS decreased from 70% rr at 3 degreesC to 58% rr at 45 degreesC. (C) 2001 John Wiley & Sons, Inc.