Reevaluation of persistent radical effect in NMP

The persistent radical effect (PRE) originally proposed by H. Fischer was reevaluated. The original Fischer's equations for nitroxide-mediated polymerization (NMP) were examined, and new equations were derived to extend PRE treatment to higher conversions. The NMP kinetic process was divided into three stages, i.e., preequilibrium, transition period, and quasi-equilibrium, which were further analyzed separately. The kinetics for model reactions as well as for NMP of styrene and methyl methacrylate mediated by N-tert-butyl-N-[1-diethylphosphono-( 2,2-dimethylpropyl)] nitroxide ( also known as SG-1 or DEPN) were evaluated.