ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

The Formation and Decay of Free Radicals Trapped in Photopolymerized Methyl Methacrylate

A. T. Bullock, G. G. Cameron, and B. D. Nicol

Department of Chemistry, University of Aberdeen, Scotland

Abstract: Radicals trapped in poly(methyl methacrylate) gels were produced by direct ultraviolet irradiation (2537 Å) of pure monomer and by photodecomposition (3650Å) of azobisisobutyronitrile dissolved in pure monomer. It was shown by computer simulation of the resulting e.s.r. spectra that two types of radical, the propagating radical and an ally 1-type radical, were present in both cases. The thermal decay curves for both types of radical were derived, and the relative contribution of the allyl radical to the overall spectrum was found to increase during decay. It is proposed that allyl radicals can be produced both by photodegradation of the polymer and by reactions of other radicals with the unsaturated ends of polymer chains.

Full paper in Portable Document Format: 263a193.pdf

Chemical Papers 26 (3) 193–199 (1972)