Aging Characteristics of Epoxy Nanocomposites Doped With Silane-Functionalized Alumina Nanoparticles for High-Voltage Insulation Applications

Performance analysis of epoxy nanocomposites under prolonged thermal and electrical stresses is vital for their use in high-voltage applications. In this regard, this work studies the influence of (3-glycidyloxypropyl) trimethoxysilane (GPTMS) and (3-aminopropyl)triethoxy- silane (APTES) as surface-functionalization agents in enhancing the durability of epoxy alumina nanocomposites. To accomplish this, the experiments have been carried out by subjecting the samples to surface discharge aging at 10 kV for a duration of 24 h and thermal aging at 100 °C for a period of 500 h. The samples subjected to surface discharge aging are characterized through permittivity, average partial discharge (PD) magnitude, surface resistivity, Fourier transform infrared (FTIR) spectroscopy, and surface roughness measurements. Along with these, the ac breakdown voltage of these samples and changes in FTIR, permittivity, and volume resistivity caused due to thermal aging have also been found. After surface discharge aging experiments, epoxy filled with APTES-treated alumina nanoparticles has shown superior aging resistance than all other samples, exhibiting a 64% reduction in surface roughness and a 91% reduction in average PD magnitude, when compared to pure epoxy (EP). Investigation results indicate that the bonds created by surface-functionalization agents and nanoparticles (NPs) are crucial in improving the overall resistance of nanocomposite towards aging.