Simulation and Experimental Evaluation of Initiator and Surfactant Concentrations and Temperature Effects on Styrene Conversion and Polymer Particle Size Distribution in Batch Emulsion Polymerization

Effects of initiator and surfactant concentrations and temperature on styreneconversion and polymer particle size distribution (PSD) in a batch emulsionpolymerization are investigated through simulation and experimental studies.The detailed model based on population balance (zero-one model), accounting fornucleation, growth and coagulation phenomena has been used for prediction ofparticle size distribution. In checking the effect of initiator concentration on final PSD, itwas noticed that when critical micelle concentration (CMC) is kept constant, the modelcannot predict PSD very well. Thus, a correlation for calculating critical micelleconcentration has been proposed and incorporated in modelling to justify the effect ofinitiator concentration on final PSD. By increasing the initiator concentration,conversion increases and final average polymer particle size drops, resulting in abroader PSD. The results show that by reducing the surfactant concentration,polymerization rate becomes slower and the final average polymer particle sizeincreases, resulting in a narrower particle size distribution. The obtained resultsindicate that at higher temperatures, polymerization rate is higher leading to increasein total number of particles which leads to a smaller final average polymer particle sizeand a narrower PSD. In all cases good agreements are observed between simulationand experimental results.