Investigation on the Electrical Property of Nano-TiO2/Liquid Nitrogen Immersed Multilayer Composite PI Films

Abstract

In order to explore the effect of nano-TiO 2 /liquid nitrogen (LN2) impregnation on the monolayer and multilayer composite films, Titanium dioxide (TiO 2 )/polyimide (PI) nanocomposite films are synthesized by LN 2 /TiO 2 immersed, and multilayer structures (PI-TiO 2 /PI/PI-TiO 2 ) are obtained. The electrical properties of pure PI with different thickness, monolayer and multilayer PI-TiO 2 composite films are tested and analyzed. The results indicate that the breakdown strength of the thicker PI film (0.125 mm) in LN2 is lower than that of the thinner PI film (0.1 mm), and the electrical strength of monolayer composite films is lower than that of pure PI ones. The breakdown strength drops initially, and then it rises with the increasing of doping nano-TiO 2 . The relative dielectric constant (e) of monolayer composite films is higher than that of pure PI. The electrical strength of multilayer PI-TiO 2 composite films after immersed in LN 2 /TiO 2 is lower than that of the pure PI and the monolayer PI-TiO 2 composite films.