Structural changes of poly(ethylene isophtalate) subjected to gamma irradiation

The results of studies of the physico-chemical changes of a polyester, poly(ethylene isophthalate), subjected to gamma irradiation up to 1 MGy, are reported. Viscometric measurements were carried out to monitor variations of the molecular weight. Changes in the amorphous fraction of the polymer were observed by means of differential scanning calorimetry. Positron annihilation lifetime spectroscopy was used to show possible modifications of the free volume as a consequence of irradiation. The results allow us to conclude that the polymer shows a good resistance to radiation damage.