Epoxy/polytetrafluoro-wax composite coatings demonstrate remarkable wear resistance, offering rapid and durable cyclic self-healing capabilities facilitated by the “sweating” behavior of polytetrafluoro-wax

Abstract

Self-healing materials possess the remarkable ability to mend scratches or cracks in damaged material sections. However, there is a pressing need to enhance the repair time and sustainable repair capability of existing self-healing materials. In this study, by physical mixing epoxy resin (EP) and polytetrafluoro-wax (PFW), we have successfully synthesized an EP/PFW composite coating. At a temperature of 120 °C, PFW, with its low melting point, undergoes rapid “sweating” (phase change) and migration to damaged regions within the coating. This EP/PFW composite coating demonstrated outstanding efficiency in repairing scratches on various substrates, with an average repair time of a mere 77 s. The addition of PFW also resulted in a substantial reduction in the coating's coefficient of friction (79 %) and wear coefficient (64.8 %). Moreover, the EP/PFW composite coating exhibited excellent sustainable self-healing properties, retaining its impressive tribological characteristics even after undergoing 5 wear/healing cycles.