Kinetic Features of Elementary Events in the Radical Polymerization of Methyl Methacrylate under Conditions of Nitroxide-Mediated Reversible Inhibition

The kinetic features of the elementary events of initiation, reinitiation, and reversible termination in the radical polymerization of methyl methacrylate mediated by piperidine and imidazoline nitroxides are studied. The rate constants of these reactions and the constant of equilibrium between the dormant and growing chains are determined. In all the systems studied, the reinitiation rate constant and the equilibrium constant decrease during polymerization. The activity of imidazoline nitroxides in the termination reaction turns out to be an order of magnitude lower than that of piperidine ones, and the constant of interaction of both types of nitroxides with methyl methacrylate growing radicals is two and a half orders of magnitude lower than that with their low molecular weight counterparts.