Atomic oxygen resistant, low alpha, anti-static polyimides for potential space applications

Ongoing efforts to develop organic polymers for potential applications on future ultra-light weight spacecraft have focused on the incorporation of specific combinations of properties into polyimides. The target properties include space environmental durability, low solar absorptivity (alpha), and sufficient electrical conductivity to mitigate static charge build-up. Anew aromatic diamine, [2,4-bis(3-aminophenoxy)phenyl]diphenylphosphine oxide, was developed and used to prepare polyimides that exhibited improved atomic oxygen (AO) resistance and low alpha while maintaining good UV resistance. Electrical conductivity was achieved by the addition of carbon nanotubes at relatively low loading levels (<0.5 weight percent). An increase in solar absorptivity and electrical conductivity was observed with increased loading of the carbon nanotubes. In this study, three different types of carbon nanotubes were placed into an AO resistant, low alpha polyimide and the effects of carbon nanotube type and loading on electrical conductivity and alpha were investigated. The results indicate that a good balance of electrical conductivity, alpha and space environmental durability can be achieved by this approach.