Monte Carlo simulation of the dispersion polymerization of styrene

The Monte Carlo kinetic simulation method was performed to simulate the entire process of the dispersion polymerization of styrene stabilized by polyvinyl pyrrolidone (PVP) in ethanol. The equilibrium distributions of each component between the continuous phase and the particle phase were calculated by a thermodynamic model. In order to calculate the time course of the concentration of different species in each phase a kinetic model was proposed for the mechanism of dispersion polymerization which took into account the reactions both in the ethanol phase and particles. The role of the stabilizer and aggregation by Brownian diffusion and aggregation by the shear stress of the fluid was quantified for simulating the time course of particle concentration and particle size. The simulation results indicated that aggregation due to Brownian diffusion was the dominant mechanism of aggregation in dispersion polymerization. The effect of monomer concentration was investigated on the particle formation stage by simulating the monomer conversion, particle diameter and particle concentration. Subsequently, the particle growth stage was simulated after sufficient stabilizer was absorbed on the particle surface. The Monte Carlo simulation results for the monomer conversion, particle diameter and particle concentration were in agreement with experimental data.