Interfacial modification and tribological properties of ZnO nanosheet carbon fiber reinforced poly(hexahydrotriazine) composites

The weak bonding strength between the non-polar carbon fiber (CF) surface and the polymer presents a challenge for the extended friction application of CF reinforced polymer composites. Here, we present a simple electroplating and oxidation method to introduce two-dimensional ZnO nanosheets (ZnO NSs) between CF and poly(hexahydrotriazine)s (PHTs). ZnO NSs form strong C-O-Zn chemical bond with CFC and create micro-nano convex surface, which enhance the shear strength of the interface and exert a toughening effect in CFRPs. The resultant PHT/ZnO@CFC showed excellent tribological properties, the coefficient of dry friction reduced by 57%, which showed that grafting ZnO NSs significantly improved tribological applications of recyclable CFRPs, demonstrating the potential incorporation of PHTs in the field of wear resistance.