DSC and oxygen uptake studies of gamma-irradiated ethylene-propylene elastomers

The specific heat capacity of irradiated ethylene-propylene copolymer was e xamined by differential scanning calorimetry. Additional measurements on ox idative stability of gamma-exposed EPR were performed by isothermal and iso baric oxygen uptake. The c(p) differences between vacuum - and air - radiol ysis of polymers are pointed out. The oxidative irradiation environment gen erates peroxy radicals that are involved in the air-degraded samples. The c (p) dependencies on temperature determined for the two manners of irradiati on are not alike. The assessment of the thermal behavior by DSC and oxygen uptake confirms the key role of RO2. in the radiolytic and thermal degradat ion of these polymers. (C) 1999 Elsevier Science Ltd. All rights reserved.