Copolymerization of styrene and acrylonitrile in ternary oil-in-water microemulsions

Abstract

The monomer reactivity ratios of styrene-acrylonitrile (SAN) copolymerization in microemulsions, evaluated from 13C n.m.r. spectroscopic analysis, were found to be variables which not only vary with the feed molar ratio of styrene to acrylonitrile but actually depend on the molar ratio of monomers in the microenvironment of the polymerization loci. The copolymerization loci were found to be the microemulsion droplets. The calculated compositions of the SAN copolymers based on the monomer reactivity ratios that were obtained were in good agreement with the experimental values determined by elemental analysis. The glass transition temperatures of the SAN copolymers were found to decrease linearly with the increasing mole fraction of styrene in the copolymers. © 1995.