Preparation And Application Of Graphene Composite Coating

In metal corrosion control methods,coating protection is the simplest,most efficient,and cheap method.Epoxy resin is widely used because of its good adhesion,excellent chemical resistance,and good corrosion resistance.With the stringent requirements for the application of metal materials and the life expectancy of the equipment,it needs to be further modified to improve its anti-corrosion performance.In this project,the epoxy resin was mixtured with graphene due to its two-dimensional sheet structure with good barrier property and zinc powder as cathode protection.The anti-corrosion performance of the coatings were evaluated by electrochemical method and salt spray test.The effect of graphene on some important physical and mechanical properties were also examined.First,adding different kinds of graphene to the epoxy resin can improve the corrosion resistance of the coating,in which G2 graphene powder and G4 graphene powder showed relative better effect.The anti-corrosion performance is best promoted.Their low-frequency impedance modulus of the electrochemical impedance spectrum can reach 108.7 ohm and 109.6ohm,and the salt spray resistance can reach 950 hours and 1100h,It can be applied in the field of transportation,ocean engineering,energy and chemical industry.Secondlly,adding graphene powder to the low-zinc epoxy resin can achieve much better corrosion resistance of the coating,in which the zinc powder and the graphene will form a micro-conductive path,and the zinc powder plays a role of cathodic protection.The coating with 20 wt%zinc powder content of 0.8 wt%G2 or G4 graphene content and 40wt%zinc powder content of 0.5 wt%G2 or G4 graphene content showed best anti-corrosion performance and the salt spray resistance can reach 1850h 40 wt%Zn and 0.5 wt%G4 graphene system.It can be applied in the field of transportation,ocean engineering,energy and chemical industry.