EMULSION POLYMERIZATION OF VINYL-ACETATE USING A POLYMERIZABLE SURFACTANT .3. MATHEMATICAL-MODEL

A mathematical model was developed to aid in the further understanding of the growth of latex particles in the emulsion polymerization of vi nyl acetate using a polymerizable surfactant, sodium dodecyl allyl sul fosuccinate (TREM LF-40). The model incorporates the main features of the system observed experimentally: copolymerization in the aqueous ph ase, at the particle surface, and chain transfer to TREM LF-40. The re actions at the particle/water interface and, more specifically, the ch ain transfer to TREM LF-40 leading to a decrease in the average number of radicals per particle, was found to be the most significant mechan ism for explaining the difference in kinetic results found for TREM LF -40 and its nonpolymerizable counterpart. The copolymerization of viny l acetate with TREM LF-40 was also shown to slow the overall polymeriz ation rate. However, the copolymerization alone was not sufficient to account for the decreased polymerization rates observed experimentally . A combination of copolymerization and chain transfer to TREM LF-40 w as found to provide a good fit of the experimental results.