The role of polymer particles in the emulsion polymerization of vinyl acetate

Abstract

The emulsion polymerization of vinyl acetate was carried out at 50°C using sodium lauryl sulfate as an emulsifier and potassium persulfate as an initiator, and the role of the polymer particles produced in this system was studied on the basis of a previous theory. The low value of the average number of radicals per particle obtained in this work, i.e. in the range 0.01 — 0.5, is explained by introducing a mechanism of a rapid escape of monomeric radicals produced by the chain-transfer reaction which occurs dominantly in the polymer particles. Semi-empirical equations are proposed for the estimation for the average number of radicals per particle over the whole range of monomer conversion. © 1971, The Society of Chemical Engineers, Japan. All rights reserved.