Heavy ions track structure in a PETP

Differential scanning calorimetry (DSC) studies of poly(ethylenetherephtalate) (PETP) film irradiated with high energy heavy ions at high ions fluencies are reported. Thin Mylar and Hostaphan PETP films (23 mu m or 19 mu m thick) were irradiated with Ar, Dy and Pb ions of the following energies and ions fluencies: Ar - 5.5 MeV/amu, 6 X 10(11) ions/cm(2); Dy - 13 MeV/amu, 5 X 10(10) ions/cm(2) and ca. 10(11) ions/cm(2); Pb - 11.4 MeV/amu, 10(10) ions/cm(2). DSC measurements were performed in nitrogen during heating-cooling-heating cycles at heating-cooling-heating rates of: 10-10-10 degrees/min and 2-20-2 degrees/min. Significant differences between pristine and the irradiated material were observed during melting and recrystallization processes occurring on primary heating, cooling and secondary heating. They have been attributed to film amorphization during heavy ion irradiation as a result of degradation and crosslinking, confirmed by gel permeation chromatography (GPC). The decrease in crystallinity and disappearance of long range order in the highly irradiated samples have been confirmed by wide and small angle X-ray scattering (WAXS, SAXS) results and density measurements. This can also be concluded on the basis of IR spectroscopy patterns. The DSC method can be applied in studies of structural changes occurring in thin polymer films after heavy ion irradiation.