SYNTHESIS OF POLYSTYRENE WITH MIXTURES OF MONOFUNCTIONAL AND BIFUNCTIONAL INITIATORS

This work studies the bulk and nonisothermic polymerization of styrene (S) using mixtures of mono- and bifunctional initiators. The effects on polymerization rate and on molecular weight averages after changes in the global initiator concentration and in the nature of the initiat or mixtures were experimentally and theoretically analyzed. The mathem atical model was adapted from the literature to admit initiator mixtur es and to simulate the applied temperature profiles. Compared to the s tandard use of monofunctional initiators, the use of initiator mixture s that include bifunctional initiators presents the advantage of reduc ing the polymerization time, while not deteriorating the final polymer quality. The simulation program accurately describes the evolution of conversion, but exhibits some deviations with the average molecular w eights. (C) 1996 John Wiley & Sons, Inc.