Effects of degassing on dc surface flashover property of polyimide

The polymers such as polyimide are easy to initiate surface flashover in space environment, and especially the degassing phenomenon of the polymer material in space high vacuum environment will enhance the flashover process. In order the reveal the degassing effect on surface flashover, the plate polyimide sample was produced and the surface flashover testing system was established. Due to the degassing, the inorganic nanofiller modification and surface fluorination treatment technology was chosen to improve the surface flashover voltage of the polyimide. Comparing to the virgin polyimide sample, the surface flashover voltage of the modified and surface fluorinated polyimide sample increased obviously. It is considered that the nano-filler fills the stomata in the material while the surface fluorination improves the surface stability, both of which reduced the gas desorption thus the surface flashover voltage of the polyimide increases. Both methods are expected to use for the spacecraft polymers in the future to improve its safety and lifetime.