Effect of Adding Graphene Method on Corrosion Resistance of Epoxy Coatings

Orthogonal test was used to select the optimal base coating (EP) formula, and three kinds of graphene/epoxy composite coating were prepared by adding dispersant and graphene (GE-EP), coupling agent modified graphene (GK-EP), or modified graphene and dispersant (GDK-EP) in the base coating. The basic physical properties, salt spray resistance and electrochemical properties of pure epoxy coating (EP) and three graphene/epoxy composite coatings were tested, and the effects of the amount and adding method of graphene on the corrosion resistance of epoxy coatings were investigated. The results show that when the dispersant was added to the epoxy coating and the mass fraction of graphene modified by the coupling agent was 1.5%, the comprehensive performance of the coating was the best. At this time, impact resistance of the coating reached 50 cm·kg, adhesion of the coating was level 2, hardness was higher than 6 H, salt spray resistance time was up to 1,500 h, and the corrosion current density was as low as 2.039×10^-8 A/cm². The performance of GDK-EP coating with 1.5% graphene was much higher than that of EP coating.