Preparation And Study Of Properties Of Graphene And Its Oxides Modified Waterborne Epoxy Zinc-rich Coatings

Due to the excellent structure and properties of graphene and graphene oxide,respectively,they are used to modify waterborne epoxy zinc-rich coatings to prepare waterborne epoxy zinc-rich coatings with reduced zinc powder content and improved corrosion resistance.Save resources and protect the environment.The main research work in the paper consists of two parts:The first part is the preparation of graphene/waterborne epoxy zinc-rich coatings.The effects of graphene content and zinc powder content on the mechanical properties,contact angle,salt spray resistance and electrochemical properties of graphene/waterborne epoxy zinc-rich coatings were investigated.Nano-ZS90 particle size analyzer,Q25 type was used.The graphene paste was characterized by scanning electron microscopy and JEM2010F transmission electron microscopy.The microscopic topography of epoxy resin and graphene combined with epoxy resin was compared.The experimental results show that when the graphene content is 0.8wt%and the zinc powder content is 46wt%,that is,the 19wt%zinc powder in the original epoxy zinc-rich coating is reduced,the hardness of the graphene/epoxy zinc-rich coating is 3H.The property is 2mm,the impact strength is 50kg·cm^-1,the adhesion is 4.96MPa,the contact angle is?=81°,and the electrochemical impedance spectrum after coating immersion for 72h shows the largest capacitive radius,the salt spray resistance time was 960h,which was 1.9times of the salt spray resistance of the original epoxy zinc-rich coating.The graphene used in the experiment is high-quality thin-layer graphene,and the combination of graphene and epoxy resin can form a highly dense and ordered structure,thereby reducing coating defects.The second part is the preparation of graphene oxide/waterborne epoxy zinc-rich coatings.Three kinds of graphene oxides with different degrees of oxidation were prepared by Hummers method under different conditions,which were respectively recorded as GO-1,GO-2,GO-3,and three kinds of GO modified waterborne epoxy zinc-rich coatings were prepared.The coating was tested for mechanical properties and salt spray performance.From the experimental results,GO-1 was selected to investigate the graphene oxide content and zinc powder content.The mechanical properties,contact angle and salt spray resistance of graphene oxide/waterborne epoxy zinc-rich coating were respectively And the impact of electrochemical performance.The experimental results show that when the obtained graphene oxide has less oxidation degree,less oxygen-containing groups and no carboxyl group,the corrosion resistance of the coating is improved.When the GO-1 content is 0.36wt%and the zinc powder content is 44wt%,that is,the 21wt%zinc powder in the original epoxy zinc-rich coating is reduced,the hardness of the graphene oxide/epoxy zinc-rich coating is 3H,the property is 2mm,the impact strength is 50kg·cm^-1,the adhesion is 4.56MPa,the contact angle is?=79°,and the electrochemical impedance spectrum after coating immersion for 24h shows the largest radius of capacitance,the salt spray resistance time was 864h,which was 1.7 times of the salt spray resistance time of the original epoxy zinc-rich coating.