Potential of Metal Passivators in Improving the Insulation Performance of Polypropylene Films for Capacitors

Polypropylene (PP) film for capacitors inevitably contains metal ash, which leads to the deterioration of insulation performance during operation. From the point of view of inhibiting the effect of metal ash, the PP composite with the metal passivator (MP) of MD1024 is prepared in this paper to improve the insulation performance. The results show that the breakdown strength of the composite is increased by 29 %, and the conductivity reduces by 63 %. In addition, the dielectric constant is slightly increased, and the energy storage density is increased from 2.69 J/cm
³
to 4.53 J/cm
³
. A stable complex structure between the MD1024 and metal ash is formed, which inhibits the catalytic activity on oxidative degradation. Therefore, the degradation of PP is weakened and the formation of low-density regions is suppressed, which significantly improves the insulation performance of PP. This paper provides a reference for the development of high-quality PP film, which shows great potential for improving the operation stability of capacitors.