Graphene-reinforced epoxy powder coating to achieve high performance wear and corrosion resistance

The corrosion and wear resistance of organic coatings are the key factors to maintain their good function. Graphene-based polymer composites have attracted incredible attention owing to their superior physicochemical properties than polymers. In this study, the effect of graphene nanosheet (G) additives on the microstructure, adhesion behaviors, anti-wear performance and corrosion resistant of epoxy powder coatings (EP) were systematically investigated. Field emission scanning electron microscope (FESEM) results verified that the mild addition of G could enhance the compactness of EP and reduced microstructure defects such as cracks, cavities, and voids. The adhesion and tribological results confirmed that the graphene-contained epoxy powder composite coatings (G/EP) could demonstrate significant improvement compared to the EP, which potentially attributed to the high mechanical and self-lubrication properties of G nanoflakes. In particular, the electrochemical and salt spray evaluation revealed that the enhanced physical barrier protection performance and outstanding anti-corrosion capacity of the G/EP composite coating containing 0.4 wt% G. The current study provides a promising metal protection strategy for the development of graphene-enhanced organic powder coatings applied in mechanical-corrosion coupling environments. This article reveals for the first time that graphene nanosheets enhance the interfacial adhesion strength of organic powder coatings, as well as the effect on wear and electrochemical performance.