Dispersion copolymerization of styrene with vinylbenzyl-terminated polyoxyethylene macromonomer

Abstract

Macromonomer with styrenic polymerizable group was synthetized by anionic polymerization of ethylene oxide initiated by potassium vinylbenzyl alcoholate, p-Vinylbenzyl-terminated polyoxyethylene macromonomer (PEO-VB) was then copolymerised with styrene in water/alcohol continuous phase. The resulting polymer is chiefly non soluble in that medium, and the final state is polymer particles in the range 500-1000 nm in diameter stabilized by a macromonomer-rich copolymer. The conversion time curve consists of three regions. The length of nucleation period was inversely proportional to the volume ratio ethanol/water (E/W). The dependence of the polymerization rate (Rp) vs. conversion is described by a curve with two-rate intervals. The rate of polymerization increased with increasing PEO-VB and initiator AIBN concentration but was nearly independent of the volume ratio E/W. The particle number slightly increased with increasing PEO-VB and AIBN concentration. The molecular weight of graft copolymer increased with increasing the volume fraction of water, PEO-VB and AIBN concentration.