Simulation of particle size distribution of polystyrene/expandable polystyrene in suspension polymerization with the use of modified time increment Monte Carlo model

Abstract

A series of simulations with the use of a time increment dynamic Monte Carlo (MC) model for predicting the Droplet Size Distribution (DSD)/Particle Size Distribution (PSD) of Polystyrene (PS) and Expandable Polystyrene (EPS) initiated with a single stirred Parr reactor using a constant speed and ended with a double stirred Parr reactor with different speeds during polymerization. This study proposes equations for determining the density and viscosity of the continuous phase, the interfacial tension of the suspension in the presence of multiple Suspending Agent (SA), and the density of the dispersed phase in a system containing a blowing agent, which capture the synergistic effects of these materials. In addition, the effect of the sampling factor f at the MC simulation for implementing adequate initial number of droplets achieving a precise MC model was investigated. A strong correlation was observed between the experimental findings and the predictions of the MC model. This consistency was evident in various conditions, including modifications in reactor geometry, timing and type of SA introduction, increased monomer droplet volume, the application of Pentane as a blowing agent for EPS, and variations in reaction parameters. The time increment dynamic MC model could predict all variations based on any specific changes in experimental formulations.