Free-Radical Acrylic Polymerization Kinetics at Elevated Temperatures

摘要

Free-radical acrylic homo- and copolymerization kinetics are reviewed, focusing on secondary reactions that impact the polymerization rate and polymer molecular weight (MW) under industrially-relevant synthesis conditions. Dependent on the monomer type (acrylate, methacrylate, styrene), mechanisms that must be considered include chain-end depropagation, monomer self-initiation, formation and reaction of midchain radicals, and incorporation of macromonomers formed by β-scission of midchain radicals. The relative importance of these reactions varies with temperature and, for copolymerization, monomer composition. A comprehensive treatment of these complexities has been completed for polymerizations conducted up to 180 °C, but further work is required to extend the applicability of the model to even higher temperatures.