Accumulation and reactions of macroradicals and degradation of polymethyl methacrylate in sequential and combined exposure to ionizing radiation and UV light

The characteristics of degradation and formation of macroradicals in photolysis and radiolysis in conditions of sequential and combined exposure of polymethyl methacrylate to γ-radiation and unfiltered UV light in a vacuum at room temperature were comparatively investigated by ESR and viscometry. Degradation of the macromolecules was most effective in photoradiation treatment. The formation and accumulation of macroradicals and the shape of the EPR spectra changed significantly in simultaneous exposure to ionizing radiation and light. It was shown that photoradical reactions of macroradicals are the cause of accelerated degradation of polymer molecules in photoradiation irradiation