Propagation Rate Coefficient for Acrylic Acid Polymerization in Bulk and in Propionic Acid by PLP-SEC Method: Experiment and 3D Simulation

The propagation rate coefficient (kp) plays a crucial role in the kinetics of radical polymerization. In this study, kp values are determined for the polymerization of acrylic acid (AA) in bulk as well as in its saturated analogue, propionic acid (PA), at 25 °C by the pulsed-laser polymerization–size-exclusion chromatography method (PLP–SEC). The kp values for AA are found to depend on the number of pulses used in the PLP experiment. The 3D simulation reveals that this dependency is partially attributed to the increase in temperature due to the heat release during polymerization with increasing conversion. A 3D simulation-based procedure is developed to recommend the PLP conditions providing the kp values free from this dependence. Interestingly, the kp values determined for the polymerization of AA in PA increase with the AA content.