Effect of Antioxidant on Irradiation Resistance of PP Composites for Nuclear Cable Insulation

This study investigates effect of antioxidants on irradiation resistance of polypropylene (PP) utilized as insulation materials for nuclear cables. Samples comprising isotactic PP (iPP) and Irganox 1010 of 0.1 wt% are irradiated using a Cobalt-60 gamma-ray at the dose range of 0 to 250 kGy. Trap distribution and AC breakdown strength are measured to evaluate the electrical performance with irradiation. The microstructure of the sample is analyzed using Fourier transform infrared spectroscopy (FTIR). Results reveal that unirradiated samples with Irganox 1010 (P10) exhibit shallower traps, but such samples demonstrate improved irradiation resistance with increasing doses. Compared with PP samples, P10 samples exhibit weakened oxidation, a marginal decrease in melting point, deeper carrier traps, and higher AC breakdown strength after the irradiation. However, the positive effect of Irganox 1010 on PP becomes less distinct with increasing irradiation dose.