An intelligent self-lubricating organic-inorganic hybrid epoxy-based coating based on the “snowboard” effect

The inherent brittleness, weak mechanical strength, and low wear resistance of epoxy resins (EP) have hindered their further application in protective coatings of mechanical parts. Herein, the soft organic polymer polytetrafluorowax (PFW) was embedded into the EP matrix under 120 °C to improve the mechanical stability and self-lubricant capability of organic resin matrix. Subsequently, multilayer graphene was obtained and functionalized by the sodium p-aminobenzene sulfonate (SPABS)-assisted mechanical exfoliation process, which was introduced into the EP@PFW polymer matrix to build a continuous inorganic reinforcement network. The “snowboard effect” generated by SPABS-G and PFW promotes load transfer and shear slipping during friction process and enhances the frictional stability of G/EP@PFW coatings. Compared to the EP/PFW coatings, the excellent heat transfer property of graphene promotes the rapid transfer of frictional heat within the G/EP@PFW hybrid coating and the dissipation of frictional energy, leading to a decreased friction coefficient from 0.16 to 0.07 (a decrease of 56.3 %, dry condition), and a decreased average wear track width from 0.56 mm to 0.36 mm (a decrease of 35.7 %). Importantly, the continuous graphene network leads to a greatly improved thermal transformation capability of the hybrid coatings, promoting its phase transition and substance migration in thermal environments and enabling self-repairing of a wide range of damages (abrasions and severe scratches) within tens of seconds.