Determination of the rate constants of recombination of macroradicals and stable radicals via the competitive-inhibition method
Abstract
The rate constants of recombination, k X, of propagating radicals with nitroxides in pseudoliving radical polymerization are determined via the competitive-inhibition method with the use of ESR spectroscopy. This method is applicable to determination of k X in the reactions of propagating radicals of styrene, acrylic acid, and methyl methacrylate with two stable radicals, the nitroxide diethylphosphono-2,2-dimethylpropyl nitroxide and the phenoxide galvinoxyl. The values of k X determined at 50 C increase in the following sequence: diethylphosphono-2,2-dimethylpropyl nitroxide-TEMPO-galvinoxyl. The selectivity of the low-activity propagating radicals of styrene in reactions with stable radicals is shown. © 2013 Pleiades Publishing, Ltd.