KINETICS OF LONG-CHAIN BRANCHING IN EMULSION POLYMERIZATION .2. VINYL-ACETATE POLYMERIZATION

The loci of polymerization in emulsion polymerization are the polymer particles, with diameters usually in the submicrometre range. The effe ct of such compartmentalization of the reaction system on the molecula r weight distribution development in non-linear polymerization is inve stigated by application of newly developed simulation models for emuls ion polymerizations that include chain transfer to polymer and termina l double bond polymerization. Kinetic parameters and experimental data for vinyl acetate polymerization reported by Friis et al. (I 974, 197 5) are used. It was found that the effect of compartmentalization must be accounted for in vinyl acetate emulsion polymerizations. and that the kinetics of long-chain branching in this reaction system needs car eful reinvestigation using an appropriate reaction model and analytica l techniques with higher precision.