Antioxidant action in irradiated polypropylene studied by ultraviolet spectroscopy

Ultraviolet spectrum of 0.2 mm thick film of polypropylene containing 0.5% ORGANOX 1010 showed that in the sample prepared by slow cooling about 15% o f the antioxidant reacted during the preparation process. The difference in turbidity between the samples obtained in the slow and the fast cooling pr ocess is attributed to the degree of crystallinity, which is in agreement w ith the DSC data. Very pronounced effects of the oxygen concentration and t he degree of crystallinity on antioxidant uptake in irradiated polypropylen e films were observed and discussed. It was also shown that a Febetron 707 pulsed electron accelerator is capable of producing both the single pulse d ose (50 kGy) and the dose rate (2.5 TGy/s) large enough to enable a compari son of dose rate effects and LET effects in the study of the antioxidant re actions in polypropylene. (C) 1999 Published by Elsevier Science B.V. All r ights reserved.