A study of the degradation of polymers irradiated by Cn+ and On+ 9.6 MeV heavy ions

Abstract

Polypropylene (PP), polyethyleneterephthalate (PET), polycarbonate (PC) and poly(ether–ether–ketone) (PEEK) foils were irradiated with 9.6 MeV Cn+ and On+ ions at fluences of 1010–1013 cm−2 simultaneously with heavy-ion energy-loss experiments and energy straggling measurements in polymers. Structural and compositional changes of the polymers after the irradiation are very important for the estimation of these effects in connection with the experimentally determined ion energy losses. Rutherford backscattering spectrometry (RBS) and elastic recoil detection analysis (ERDA) were used for elemental composition study, whereas UV–visible spectrum study (UV–Vis) and Fourier transformation infrared spectroscopy (FTIR) were utilised to follow the structural changes (polymeric functional group appearance, double bonds, carbon-cluster creation etc.) of the irradiated polymers. Heavy-ion irradiation causes a release of hydrogen and oxygen from the polymers penetrated by the ion beam, chemical and structural changes, the new appearance of radicals, and polymeric-chain cross-linking especially at ion fluences above 1012–1013 cm−2. The compositional and structural changes related to the ion species, ion-irradiation fluence and the type of polymer were studied and discussed in connection with the energy-loss measurement.