Modelling and optimization of process variables for the solution polymerization of styrene using response surface methodology

A satisfactory model for predicting monomer conversion in free radical polymerization has been a challenge due to the complexity and rigors associated with classical kinetic models. This renders the usage of such model an exciting endeavour in the academia but not exactly so in industrial practice. In this study, the individual and interactive effects of three processing conditions (reaction temperature, reaction time and initiator concentration) on monomer conversion in the solution polymerization of styrene using acetone as solvent was investigated in a batch reactor through the central composite design (CCD) model of response surface methodology (RSM) for experimental design, modelling and process optimization. The modelled optimization conditions are: reaction time of 30 min, reaction temperature of 120 °C, and initiator concentration of 0.1135 mol/l, with the corresponding monomer conversion of 76.82% as compared to the observed conversion of 70.86%. A robust model for predicting monomer conversion that is very suitable for routine industrial usage is thus obtained.