MODELING POLY(VINYL ALCOHOL)-STABILIZED VINYL-ACETATE EMULSION POLYMERIZATION .2. COMPARISON WITH EXPERIMENT

The mathematical model presented in Part I, accommodating the emulsion polymerization of vinyl acetate stabilized with poly (vinyl alcohol), predicts experimental conversion and particle size data with reasonable accuracy. Model predictions of measurable variables exhibit sensitivity to variables affecting either primary ungrafted particle nucleation or flocculation kinetics, but are relatively insensitive to variables affecting poly (vinyl alcohol) grafting reactions and the resulting primary grafted particle concentration. Semibatch simulations indicate that independent increases in the vinyl acetate, poly(vinyl alcohol), and initiator levels all increase the primary grafted particle population. It is unlikely, however, that this population exceeds the ungrafted counterpart under most commercial polymerization conditions. This relative insignificance of grafting during particle nucleation is also noted in literature data simulations where, with appropriate parameter adjustments, the model predictions agree well with the batch, thermal initiation data.