FTIR Analysis of Partial Discharge-initiated Polyimide Nanocomposites Degradation and Insulation Durability under High Frequency Ac Voltage Stress

For the sake of investigating the contribution of inorganic nanoparticles in reduction of partial discharge (PD) activity, and insulation durability, PI/TiO
₂
nanocomposite thin films were fabricated with weight percentage of 2 and 3 via in-situ polymerization. PD aging tests were carried out for both the pure and PI/TiO
₂
nanocomposite films to collect partial discharge data until the insulation breakdown occurred in order to analyze the nanoparticles impact on partial discharge characteristics parameters and insulation durability i.e. PD number per cycle and per second and maximum PD amplitudes. FTIR analysis were conducted for both aged and unaged pure polyimide (PI) and PI/TiO
₂
nanocomposite samples for investigating bonding structure and the interactions happening between nanoparticles and polyimide matrix at the interface. Based on bonding structure analysis, it was noticed that incorporation of nanoparticles into polymer matrix introduces abundant amount of hydrogen bonds between TiO
₂
nanoparticles and -OH groups, which offers hitch to partial discharge occurrence resulting greater insulation lifetime and durability. Besides, less degradation had been observed in aged PI/TiO
₂
nanocomposites as compare with aged unfilled PI.