Rectorite/polyimide films with superior atomic oxygen resistance by a dual-protection strategy

Abstract

Polyimide (PI) has become an indispensable key material for low-Earth orbit (LEO) spacecraft due to its excellent performance. However, it is highly susceptible to atomic oxygen (AO) erosion, which severely limits the service lifetime of spacecraft. Herein, a dual-protection (matrix modification and coating) strategy is proposed to improve the anti-AO capacity of PI by introducing rectorite nanosheets (RNs) with outstanding AO resistance. The dual-protected rectorite/PI film shows lower AO erosion yield (only 4.04% of the pristine PI film) and more stable mechanical properties after AO irradiation. The AO-resistant mechanism is attributed to the blocking and adsorbing AO of RNs based on the experiment investigation and molecular dynamic simulation. The key advantage of this method is that, even if the coating is compromised, the RNs embedded in the matrix can still provide resistance against AO erosion. Consequently, this protection strategy provides a new approach for constructing superior AO-resistant PI films applicable in LEO conditions. • Rectorite nanosheets are simply and quickly fabricated by ball milling • Dual-protected rectorite/polyimide films show exceptional atomic oxygen resistance • The advantages of the dual-protection strategy are thoroughly explored • The blocking and adsorbing mechanisms of rectorite nanosheets are deeply revealed