A model was proposed for simulation of a particle formation stage in the dispersion polymerization of styrene in ethanol. The role of poly(N-vinylpyrrolidone) molecules grafted by a polystyrene oligomer (PVP-g-PS) was taken into consideration for the particle stabilization. The model was derived based on the following mechanism: (i) polystyrene molecules whose degree of polymerization is greater than j cr precipitate and form particles, (ii) particle aggregation due to the Brownian diffusion and the shear stress of the fluid continues until the amount of the PVP-g-PS molecules is enough to cover all the particle surface, and (iii) particles do not aggregate with each other once the entrire particle surface is covered with the PVP-g-PS molecules. The theoretical particle concentrations calculated using the present model under various monomer concentrations and stirring speeds were in good agreement with the experimental data.

A model is proposed for simulating the particle growth in the dispersion polymerization of styrene in ethanol. The model is based on the following assumptions: (i) the termination reaction in an ethanol‐phase and the chain‐transfer reactions in the ethanol‐phase and particles can be neglected, (ii) the mean volume of the radicals captured by particles is approximately equivalent to that of monomeric radicals, and (iii) the termination rate constant in particles is βgel times that of the ethanol‐phase. The experimental results of the conversion, the particle diameter and the particle number measured at the reaction time of 2 h were used to determine the initial conditions. When the termination rate constant in particles was taken to be about 1/130 of that of the ethanol phase, the calculation results of the conversion and the particle diameter were in good agreement with the experimental data.