Improved atomic oxygen erosion resistance of the carbon fibre–epoxy interface with polyhedral oligomeric silsesquioxane

Polyhedral oligomeric silsesquioxane (POSS) was grafted onto the surface of carbon fibres (CFs) to fabricate carbon fibre/epoxy (CF/EP) composites with improved interlaminar shear strength (ILSS) and atomic oxygen (AO) erosion resistance. POSS-CF was prepared by reacting amine groups on the pretreated CF surface with the POSS to form a continuous uniform layer of siloxane oligomers. X-Ray photoelectron spectroscopy, scanning electron microscopy and Fourier transform infrared spectroscopy demonstrated that POSS was successfully grafted onto the CF surface. The ILSS and AO erosion resistance of the POSS-treated CFs and CF-EP interface were improved because a SiO₂ passivation layer formed with AO exposure, especially with POSS-EP0409. This is an effective solution for enhancing the interfacial bonding force and interfacial AO erosion resistance for the low-Earth orbit environment.