Radiation chemistry of poly(ethyl methacrylate)—I. Interpretation of ESR spectra

ESR spectra of poly(ethyl methacrylate) γ-irradiated in vacuum at different temperatures were studied in different conditions. The change in the relative intensities of the four-and five-line components of the conventional nine-line spectrum is investigated in detail with respect to changes in the absorbed dose, irradiation, and decay temperatures. It is assumed that the propagating radical is the single radical type responsible for thecharacteristic nine-line spectrum. It is also found that a stable minor radical, quite probably of allyl or polyenyl type, giving a weak broad line, also overlaps the four-line component of the nine-line spectrum.