Enhanced high-temperature tribological performance of PTFE/PI fabric composites by simultaneously introducing PDA/SiO₂ hybrid coating and aramid product reinforcements

Surface modification with polydopamine (PDA)-based coating is widely used to obtain high performance and build special functions for modified surfaces. Herein, a mussel-inspired nanohybrid coating (PDA/SiO₂) was first co-deposited onto the polytetrafluoroethylene (PTFE)/polyimide (PI) fabric surfaces via simultaneous polymerization of dopamine and hydrolysis of the tetraethoxysilane (TEOS) in a simple one-pot method. This nanohybrid coating could afford the hybrid-fabric sufficient active groups, improved surface roughness, and wettability without compromising fiber intrinsic strength. As a result, the interfacial bonding strength between fabric and PI resin matrix presented a significant increase as measured by the peeling tests. In addition, aramid pulp and aramid fiber powder were incorporated into the fabric composites to construct synergistic enhancement effects with PI fibers on bearing capacity and wear resistance. Results showed that the fabric@PDA-TEOS/micro-powder composites presented the best high-temperature anti-wear property resulting from the improved interfacial adhesion strength and carrying capacity of lubricant films.