| Metal corrosion brings a lot of waste and potential dangers,and brings a huge burden to the national economic production.Anti-corrosion coating is an effective method to slow down metal corrosion,which is widely used in bridges,construction,machinery and other fields.Waterborne epoxy resin is an environmentally friendly material with VOC content of 0.It is widely used in anti-corrosive coatings.However,due to the volatilization of solvent water in waterborne epoxy resin coatings,a large number of voids and tiny channels are left,which accelerates the absorption of water and the penetration of salt.Microporous fillers are needed to improve the corrosion resistance.Aluminum dihydrogen tripolyphosphate(ADTP)is an excellent flaky corrosion-resistant micrometer pigment,which complexes with metal ions to form passive film to prevent ions from penetrating into the substrate;graphene oxide(GO)is a two-dimensional nano-material,which can prolong the penetration path of electrolyte and absorb metal ions to promote the decomposition of pigments;calcium oxide(CaO)is a pigment modifier and can provide alkaline environment,combined with phosphate to produce more insoluble calcium phosphate.Adding them to the coatings can achieve both physical and chemical anti-corrosion effect,showing ideal synergistic effect.In this paper,the synthesis of ADTP,GO,ADTP/GO,ADTP-GO,ADTP/CaO,ADTP/CaO-GO was introduced.XRD,FTIR,UV-Vis,SEM and other methods were used to characterize the material.The results show that the material has been successfully prepared.The morphology changes and material composition of ADTP,GO,CaO hybrid system were analyzed.It was found that GO composite ADTP was more beneficial to corrosion protection than adsorbing ADTP.CaO modified ADTP produced calcium hydrogen phosphate and aluminum phosphate.In addition,water-borne epoxy coatings with different proportions and contents of ADTP,GO,ADTP/GO,ADTP-GO and ADTP/CaO-GO were prepared.The coatings were characterized by Electrochemical Impedance Spectroscopy and Tafel electrochemical test methods.Their equivalent circuits were simulated,the changes of the equivalent components were analyzed,and their electrochemical corrosion process was studied.It was found that among the anticorrosive coatings prepared,ADTP had better anticorrosive property when the content of ADTP was 30%,GO had better anticorrosive property when the content of GO was 0.1%,ADTP/GO had the worst performance at 150:1,ADTP-GO coatings had better anticorrosive property than the above coatings,and the slurry of ADTP and CaO had better comprehensive anticorrosive property when the ratio of ADTP to CaO was 4:6. |
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