Mechanisms and Conditions that Affect Phase Inversion Processes. The Case of High‐Impact Polystyrene

Abstract

The phase inversion (PI) during the bulk polymerization ofthe styrene?polybutadiene system (high impact polystyrenemanufacturing process) is empirically and theoreticallystudied in this article. In the experimental work, a series ofreactions were performed with benzoyl peroxide as initiatorand at temperatures considered of industrial interest (80Cand 90C), varying also the reactor stirring level. PI wasdetermined by offline viscosity measurements and verifiedby scanning transmission electron microscopy. The rheologicalbehavior of each reacting system was analyzed andan empirical correlation to predict its apparent viscosityfrom fundamental reaction parameters was derived. Thiswas achieved successfully for both before and after the PIpoint.