Improvement in Radiation Stability of EPDM by Efficient Antioxidants

摘要

This paper analyses the stabilization effect induced by the presence of several compounds with antioxidant features (oleanolic acid, quercetin, capsaicin, metallic selenium and rosemary extract). The investigation are carried out for different additive concentrations (0, 0.25, 0.50 and 1% w/w), as well as for pairs of metallic selenium with the other four compounds. For antirad contribution to the delaying of radiochemical oxidation, modified and pristine EPDM samples were irradiated in GAMMATOR machinery provided with ~(137)Cs source. While dose rate is 0.4 kGy.h~(-1), the total doses were 0, 10, 20 and 30 kGy, which are specific for radiosterilization. The results are obtained by application of two complementary techniques: isothermal chemiluminescence (180 °C) and FT-IR spectroscopy. From chemiluminescence determinations oxidation induction times and rate of oxidation were calculated as the main kinetic characteristics depicting the progress in the oxidative degradation of polymer substrate. FT-IR spectroscopy allows us to evaluate the evolution of hydroxyl and carbonyl accumulations.