Preparation And Properties Studying Of Graphene/Waterborne Epoxy Zinc Rich Coating

Waterborne epoxy anticorrosion coating,which is environmental friendly,no volatile organic compounds,is the future development trend of paints.However,the poor comprehensive performance of the waterborne epoxy anticorrosive coating limits its use in marine heavy duty field.In this paper,the waterborne epoxy zinc rich coating was first prepared,and then the graphene was added into the coating to obtain graphene /waterborne epoxy zinc rich coating with excellent performance.Four kinds of graphene,such as graphene nanosheets,graphene powder,graphene oxide(Electrolysis)and graphene oxide(Hummers)were respectively added into the coating and the effects on the properties of the graphene/epoxy composite coatings were also discussed.Finally,the economic and social benefits of the graphene/epoxy composite coatings were analyzed.Waterborne epoxy resin was prepared by chemical modification method and optimized by parallel test.The p-phenylenediamine was used as the main amine compounds in curing agent and optimized by orthogonal test.The waterborne epoxy resin and curing agent were characterized by malvern nanoparticle size analyzer,rotary viscometer,infrared spectrometer and SEM.Small particle size,high stability,low viscosity waterborne epoxy resin and curing agent were obtained.Effects of curing agent addition and pigment volume concentration in coatings were studied.The results showed that the waterborne epoxy zinc rich coating displayed excellent salt spray resistance(800 h),adhesion(grade 0),flexibility(1 mm)and hardness(2 H)with the molar ratio of epoxy group to active hydrogen 1.4:1,and the pigment volume concentration 35%.Effects of the mass fraction of four kinds of graphene materials on the properties of graphene/epoxy composite coatings were studied and analyzed.Experimental results showed that the corrosion resistance of composite coatings were significantly improved with four materials added.The salt spray resistance of the graphene/epoxy composite coatings were 1500 h with the mass fraction of graphene oxide(Hummers),graphene nanosheets and graphene powder 0.3 wt%,0.5 wt% and 0.5 wt%,respectively.While the salt spray resistance of the coating was 1000 h with 0.5 wt% graphene oxide(Electrolysis)added.In addition,the hydrophobicity property of the composite coatings was improved to some extent.Cost changes of graphene/epoxy composite coatings showed that the graphene nanosheets/epoxy composite coating was more economical,the graphene oxide/epoxy is relatively high and the graphene powder/epoxy is moderate.Thus,graphene nanosheets is expected to be applied largely in waterborne epoxy coatings.