Inhibitor radicals in styrene polymerization

Stable radicals derived from inhibitor molecules were detected in the process of styrene polymerization. N-(1,4-dimethylpentyl)-4-nitroso-aniline and 2,4-dinitrophenol inhibitors were shown to produce nitroxyl radicals. Phenoxyl radicals come from 4-benzylidene-2,6-di-tert-butyl-cyclohexa-2,5-dienone. The radical structures were determined. The kinetics of radical formation was studied. These radicals can participate in the process of living radical polymerization and significantly affect the kinetics of polymerization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1599–1603, 2004