The impact of air relative humidity on corona-resistant polyimide film

To study the impact of the air relative humidity on the corona-resistant polyimide film properties, the DuPont Kapton100CR films were put in home-made salt shakers that filled with particular saturated solution, and the measurement on conduction current and corona-resistant aging of the films were carried out respectively at room temperature (296K). The result of conduction current testing showed that: in the same relative humidity condition, the conduction current of polyimide film increase with the increase of the electric field. And with the relative humidity rise, the curve of conduction current moved upward. At the meantime, the electric degradation threshold would decrease. The corona-resistant test showed that corona-resistant aging decreased logarithmically with the increase of the relative humidity.