Model Studies of Nitroxide‐Mediated Styrene Miniemulsion Polymerization – Opportunities for Process Improvement

Abstract

Abstract Modeling studies were performed to investigate how persulfate‐initiated nitroxide‐mediated styrene miniemulsion polymerizations are influenced by changes to the polymerization recipe. By manipulating the initial concentrations of potassium persulfate and nitroxide, and the aqueous phase volume, trends in the predicted polymerization time, number average molecular weight, polydispersity and degree of polymer livingness were identified that indicate operating conditions for improved process performance. Specifically, our model predicts the existence of experimental conditions that simultaneously minimize polymer polydispersity and maximize the livingness of the polymer. The mechanisms responsible for the predicted trends were identified from the predicted molecular weight distributions of the living and dead polymer chains. Predicted number MWDs at 20% monomer conversion for styrene NMMP systems employing various levels of [ KPS ] aq ,0 . Dormant KPS‐initiated polymer radicals. image Predicted number MWDs at 20% monomer conversion for styrene NMMP systems employing various levels of [ KPS ] aq ,0 . Dormant KPS‐initiated polymer radicals.