Radiation effects on dielectric properties of ethylene propylene rubber

In order to evaluate the radiation degradation of ethylene propylene rubber (EPR), radiation effects on EPR was investigated by using dielectric analysis and thermal-gravimetric analysis. Permittivity, loss factor, tan δ and thermal decomposition temperature were observed for γ-ray irradiated EPR. As radiation dose increased, the peak temperature of loss factor and tan δ of EPR increased, and loss factor and tan δ at peak temperature decreased. Activation energies were calculated using loss factor and thermal decomposition for γ-ray irradiated EPR as well. The trends of both calculated activation energies showed same tendencies as radiation dose was increased.