Improved Dielectric Properties of Polypropylene Films Based on Aromatic Compounds

In the paper, the polypropylene (PP) films doping with m-amino benzoic acid (MAA) were prepared for increasing the dielectric strength of power capacitors. In order to investigate the effect of MAA on electrical properties, the DC breakdown strength and conductivity under different temperatures were tested and analyzed. The results show that by addition of 0.01 wt% MAA in PP films, the breakdown strength increased 18.6% than that of the pure PP film at 25 °C. DC conductivity also possessed a superior at different temperatures, which means the lower conductance loss and less heat accumulation. Besides, the isothermal discharge current (IDC) testing and quantum chemistry method were used to analyze the mechanisms and provide an effective criterion to assess the efficiency of aromatic compounds. The aromatic compounds may be a feasible way to optimize the insulation property of PP films and show great potential in the power capacitors.