Research on the Polyimide Aerogel as a Light-weight Insulating Material with High Dielectric Strength

In this article, the insulation characteristics of polyimide aerogel as an ultralight weight insulation material is investigated. The breakdown characteristics of polyimide aerogel films under different nitrogen pressure are measured, and the partial discharge characteristics during breakdown process are recorded. It is found that the breakdown strength of PIA shows a “U-shaped” trend with the rising gas pressure, with a maximum breakdown strength of 117kV/mm at 0.05MPa, and minimum strength of 48kV/mm at 0.5MPa. These characteristics are closely related to pore distribution inside polyimide aerogel. Micro morphology of breakdown point of polyimide aerogel suggests the gas discharge-dependent breakdown mechanism. Above test results show that polyimide aerogel has excellent insulation characteristics at low pressure, making it one of the alternative materials for light weight electrical insulation of aircraft, ship, and other equipment.