Mechanism analysis of improved corona-resistant characteristic in polyimide/TiO2 nanohybrid films

Polyimide/TiO2 nanohybrid films with good corona resistance were prepared by using in situ dispersive polymerization. Effects of the concentration of nano-TiO2 fillers and the corona aging time on the dielectric properties of the films were explored. Results showed that the corona resistance of the hybrid films could be improved with increasing the concentration of TiO2 fillers, and the corona resistance was dependent on the dielectric permittivity of the hybrid films. The mechanism of the corona resistance was also discussed by analyzing the change in electric field and the electron action of TiO2 fillers based on the Fermi–Dirac statistic.