Theoretical Expression of the Average Activation−Deactivation Equilibrium Constant in Controlled/Living Free-Radical Copolymerization Operating via Reversible Termination. Application to a Strongly Improved Control in Nitroxide-Mediated Polymerization of Methyl Methacrylate

摘要: The average activation−deactivation equilibrium constant, 〈K〉, was determined on a theoretical basis for controlled free-radical copolymerizations operating via reversible termination mechanism (i.e., nitroxide-mediated polymerization or atom transfer radical polymerization), using the terminal model and implicit penultimate unit effect propagation reaction. From equation, it shown that addition of small fraction an appropriate comonomer to monomer with very large K, might lead strong reduction providing added exhibits low K. In polymerization, monomers high such as methacrylic esters, do not in presence nitroxides like SG1, despite absence disproportionation reaction between nitroxide growing radical, because too fast ir...