MODELING AND SIMULATION OF SEMIBATCH EMULSION POLYMERIZATION

By taking advantage of recent theoretical developments in emulsion pol ymerization and radical polymerization kinetics at high conversion, a model is developed for simulating seeded semibatch emulsion polymeriza tion. The model is used to calculate the time evolution of the polymer ization rate, the monomer conversion, the instantaneous degree of poly merization, the monomer concentration in particles, the average radica l number per particle, and the propagation rate coefficient and termin ation rate coefficient over the whole course of the polymerization. Ex perimental observations by previous workers, including the existence o f steady-state phenomenon and the broad distributions of molecular wei ght, are reproduced in the results of the simulation. The gel effect o n emulsion polymerization and the open-loop stability of the semibatch process are discussed.