Mercaptans as promoters and modifiers in emulsion copolymerization of butadiene and styrene using potassium persulfate as catalyst. III. Calculation of molecular weights and intrinsic viscosities of polymers from mercaptan consumption data

Abstract

AbstractAn empirical equation is described which predicts the intrinsic viscosities of 75:25 butadiene‐styrene emulsion copolymers from data on mercaptan consumption. The form of the equation is as follows: where [η] is the intrinsic viscosity, P is the conversion, R is the fraction of mercaptan consumed, R0 is the mercaptan charged, and a, b, and c are constants equal to 0.22, 1.12, and 0.66, respectively. Evidence is given that the intrinsic viscosity of mutual‐recipe polymers can be described satisfactorily in terms of mercaptan consumption.