Emulsion polymerization kinetics and its reactor design. II. The MWD behavior in isothermal batch operation

Abstract

Abstract The emulsion polymerization of styrene in an isothermal batch operation can be divided into three stages, and the corresponding kinetic rate equations are obtained from the experimental conversion‐reaction time curve. The course of polymerization between the beginning of the reaction and any subsequent time is successfully computed for the reaction rate, the MWD, and the average degree of polymerization using the intergrals of these rate equations, which could readily explain the behavior of the emulsion polymerization. A comparison is made between the theoretical results and the experimental data. Both the theoretical treatment and the experimental data predict that the MWD for a typical emulsion polymerization is characterized by the rapid decrease in M w / M w ratio at the entrance of the zero‐order stage and a gradual increase in the first‐order stage regardless of an autoacceleration effect. An autoacceleration effect in the first‐order stage is, however, evidence for a typical emulsion polymerization.