Crystallization of γ-irradiated poly(ethylene oxide)

The shape of DSC thermograms and heats of phase transformations reflect the changes in crystallinity of poly(ethylene oxide) (PEO) brought into it by 60Co γ-radiation to selected doses, in air or in nitrogen. In samples irradiated in air, multiple peaks appeared presumably due to degradation in more radiation-sensitive amorphous part producing new crystals of different macroconformations, the changes increased during the post-irradiation period. Related morphological changes were detected. Additional crystallization at low doses resulted in increase of crystallization heats, further degradation reduced crystallinity at higher doses. In the samples irradiated under nitrogen crosslinking contributed to reduction of crystallinity, while crystallization temperatures decreased reflecting lower quality of crystallites.