Effect of neutron irradiation on the impedance of Epoxy-TiO2 nanocomposite for electric power insulation

Abstract

The effect of neutron irradiation on the impedance of the nano-filled polymeric based insulation materials became an important issue because of its presence in the nuclear power plant. The exposure of polymeric materials to ionizing radiation can influence the dielectric and insulating properties of the material. This work presents the influence of neutron irradiation and the presence of nanoparticle on the insulating property of Epoxy-TiO2 nanocomposite. The prepared plane nanocomposite samples were exposed to neutron radiation in the Nigeria Research Reactor I (NIRR-I) and dielectric analysis was performed over a frequency range of 20 Hz–200 kHz. The polarization relaxation process of the irradiated neat and nanocomposite is dominated by dipolar, interfacial polarization, and free radicals. The presence of TiO2 nanoparticles in epoxy composite resulted in improved impedance after irradiation when compared with the non-irradiated and irradiated neat polymer. The 1 wt% nano-filled polymer has higher impedance after irradiation and followed by the 2 wt% nano filled polymer. The impedance of the irradiated 1 wt% TiO2 nano-filled epoxy polymer increased by 8.3% and 160% when compared with the non-irradiated and irradiated neat epoxy polymer respectively. The variation of temperature of the sample revealed a consistent thermally activated process in the irradiated samples. The research suggests that filling the epoxy polymer with 1 wt% TiO2 nanoparticle can modify the dielectric and the polarization relaxation behaviour of the polymer composites. This could enhance the resistance of the polymer composite to radiation-induced degradation in the polymeric insulation.