Enhanced Breakdown Strength of Polypropylene Film by Molecular Semiconductor Addition

In the long run, the next generation of smart grid put forward higher requirements on the insulation properties of power capacitors. Therefore, there is an urgent demand to increase the breakdown strength of PP film. In recent years, doping with inorganic nano-fillers was often used to improve insulation performance. However, these methods inevitably led to the increase of dielectric loss and deterioration of mechanical properties, which were not suitable for practical applications. As a result, we proposed an all-organic PP-based composite which mixed by PP and the perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) as molecular semiconductor, and also investigated its morphological characteristics and electrical properties in the study. The results have shown that the molecular semiconductor introduced a large number of deep traps in the PP film, thereby inhibiting carrier transport and increasing the breakdown strength. This work proved that the doping molecular semiconductor is an effective method to improve the insulation performance for PP-based dielectric material.