A new approach for the kinetic modeling of free radical bulk polymerization of styrene

The kinetics of styrene-free radical bulk polymerization was studied by differential scanning calorimetry (DSC). The data obtained from DSC thermograms were used to model and predict the autoacceleration during styrene polymerization and to understand how it is influenced by temperature. The experimental data were well described by the estimated kinetic model. The model included two processes (the first-order reaction and autoacceleration), because they occur simultaneously as two parallel reactions rather than being strictly separated. It was found that the autoacceleration activation energy is approximately four times lower than the energy of the first-order reaction. In addition, the first-order reaction followed by the autoacceleration of the styrene-free radical bulk polymerization occurs simultaneously only between 41.7 and 110.5 °C. A new kinetic model of styrene-free radical bulk polymerization was developed. Experimental data of styrene conversion dependence on reaction time were well described by estimated kinetic model. It was determined that the first-order reaction followed by autoacceleration of styrene-free radical bulk polymerization is taking place simultaneously between 41.7 and 110.5 °C.