Study On Anticorrosion Performance Of Nanocoposite Waterborne Coating Based On Graphene

In recent years, environmentally friendly waterborne anticorrosion coating has become an important research orientation of the metal surface treatment. Graphene has attracted much attention due to their advantages of excellent barrier property,electrochemical performance, and environmental friendliness.In this paper, graphene/ epoxy silane coupling agent or graphene/acrylate latex composite surface-treating agent were applied for the corrosion protection of galvanized sheet, which were prepared by using aqueous dispersion of grapheme as nano-additive and epoxy silane coupling agent or acrylate latex as film-forming material via solution blending methods. Effects of the species and dosage of corrosion inhibitor on the anticorrosion performance of nanocoposite waterborne coating based on graphene were investigated.Anticorrosion performance of nanocoposite waterborne coating based on graphene were characterized by Tafel polarization curve, electrochemical impedance spectroscopy and neutral salt spray accelerated test. The results show that: when the graphene content in graphene/ epoxy silane coupling agent composite surface treatment solution is 2.0 % of silane oupling agent, the composite coating exhibited the best anticorrosion property. Corrosion current density decreased and the polarization resistance of the nanocomposite coating increased by adding different kinds of corrosion inhitor. When the dosage of phytic acid, ammonium metavanadate,ammomium molybdate and polypyrrole is 0.40%, 0.08%, 0.04%, and 0.09%,respectively,the nanocomposite coating inhibited the corrosion rate of the galvanized steel and exhibited the best anticorrosion property. For graphene/acrylate latex composite surface-treating agent, the anticorrosion performance of composite coating was the best when the content graphene is 0.20% of solid content of acrylate latex,The anticorrosion performance of the composite coating were improved due to the decrease of corrosion current density and increase of the polarization resistance when the amount of phytic acid, sodium vanadate, sodium molybdate, and polypyrrole used in the graphene/acrylate latex composite surface-treating solution, is 0.60%, 0.08%,0.04%, and 0.10%, respectively.