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In this work, the effect of electron beam (EB) irradiation on polypropylene (PP) films has been studied via different techniques, namely: x-ray diffraction and UV–Vis absorption spectroscopy. The PP films were irradiated with a 1.5 MeV electron beam at doses of 5, 10, 20, 50, 70, 100 and 120 kGy. The crystallinity of the PP films was found to increase, slightly, by EB irradiation. The changes in the dipole strength, transition dipole moment, oscillator strength, optical band energy gap and activation energy have been investigated as a function of the irradiation dose. The results exhibited an increase in both the dipole moment and the oscillator strength; meanwhile, a decrease was found in both the energy gap and the activation energy with increasing dose. The obtained results explored a linear relation plotted between each of the dipole moment, the oscillator strength and the activation energy and the irradiation dose that showed good correlation coefficients. The results suggest the possible use of this polymer as a dosimeter for electron beams in the dose range of interest (0–120 kGy) by means of UV–Vis spectrophotometry.

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Electrical resistivity of the unplasticized poly(vinyl chloride) copolymer (UPVC) films irradiated with high-energy proton beams was studied with reference to a control sample, as a function of both ion energy and ion dose. Upon irradiation with beam energy ranging from 25 up to 37 MeV and at a beam fluence of 0.225×1010 ion cm-2, the room-temperature resistivity of the insulating films decreased by four orders of magnitude from its original value. Furthermore, using 25 MeV proton beams over a wide range of fluence (1011-1015 cm-2), the room-temperature resistivity of the films decreased by only three orders. Then, the dependence of the resistivity ρ(T) on the ion energy and fluence was also observed as the temperature T was progressively increased up to 373 K. The observed behaviour of ρ(T) agrees with the charge transport model, consistent with a hopping mechanism in the polymer. In addition, the changes in the ac electrical resistivity of the irradiated UPVC films have been measured within the temperature range (293-373 K) and at different frequencies (100 kHz-3 MHz).