Effect Of Graphene And Graphene Oxide On Properties Of Organic Resin Composite Coatings

In the marine environment,corrosion of metals poses a great threat to ships and offshore platforms in which it operates.Organic coating protection is the simplest and most economical anti-corrosion technology.However,common organic coatings have their own deficiencies that limit the application of the coating.Therefore it needs to be modified to improve the performance of the coating.Graphene and graphene oxide have many excellent properties such as high specific surface area,strong surface adsorption,and large surface energy,etc.It is beneficial to improve the overall performance of the resin after being mixed with the resin.In this paper,fluorocarbon resins,epoxy resins and waterborne polyurethanes are used as the resin matrix,G and GO are used as fillers,spin coating method is used to prepare a series of G/resin and GO/resin composite coatings on the surface of low carbon steel.The structure of G and GO was characterized by infrared spectroscopy and field emission scanning electron microscopy.The hydrophobicity,adhesion and microhardness of the composite coating were studied by static contact angle tester,pullout tester and microhardness tester.The corrosion resistance of the composite coating was studied by salt spray test and electrochemical impedance spectroscopy.The studies show that the G surface contains functional groups such as hydroxyl and carboxyl groups,while the GO surface also contains carbonyl groups and epoxy groups,which shows higher surface activity.It is found through scanning electron microscopy that both G and GO are present in complex folds.Through the study of the physical properties and anti-corrosion properties of the composite coating,Graphene can improve the contact angle of the coating to a certain extent,while graphene oxide can reduce the contact angle of the coating,both of which have a significant effect on the bonding strength and microhardness of the coating.The bonding strength of graphene to the three coatings increased by 44.3%,80.1%,and 73.5%,respectively,and the bonding strength of graphene oxide composite coatings increased by 57.8%,67.5%,and 171.2%,respectively;due to the fluorocarbon coating itself The microhardness is relatively high,so the addition of G and GO,the microhardness of the composite coating increased by 22.3% and 7.4%,respectively,while the reinforcing effect of the epoxy coating and the waterborne polyurethane is obvious,and the microhardness is improved.More than 40%.The salt spray test and electrochemical impedance spectroscopy experimental study found that when the content of G and GO is low,the corrosion resistance of the coating can be improved,and for the different system resins,the optimal content of G and GO is inconsistent,and for the fluorocarbon coating The optimal contents of G and GO are 0.05 wt% for both layers and epoxy coatings.This may be due to the fact that the content of G and GO is insufficient to provide a good physical shielding effect,and that high content is prone to agglomeration and increase coating defects;For the waterborne polyurethane composite coating,the optimum content of G is 0.15 wt%,and the optimum content of GO is 0.01 wt%.This may be due to the higher activity of GO and the better bond formation with the active grouprich WPU.Cooperation,improve the protective performance of the coating.