Preparation And Properties Of F-GO Zinc-rich Epoxy Anticorrosive Coating

In recent years,with the increasing demand for oil and gas,there are more and more oil and gas pipelines.As the natural environment of oil and gas transmission pipeline is generally bad,the pipeline is prone to corrosion damage,which brings huge waste of oil and gas resources and potential safety hazards.Therefore,it is necessary to strengthen the corrosion and protection of oil and gas pipelines.Anticorrosive coating is the most simple and efficient method for pipeline anticorrosion.As a new type of carbon nano materials in the 21 st century,graphene and its derivative graphene oxide(G)and its functionalized derivative graphene oxide(GO)not only have high mechanical and thermodynamic properties,but also have high specific surface area and good impermeability.Adding them to coatings can significantly improve the comprehensive properties of coatings.In this paper,dopamine(DA)and 3-aminopropyltriethoxysilane(APTES)were used to modify graphene oxide to get functionalized graphene oxide(f-GO).By chemical modification and blending modification,the functionalized graphene oxide zinc-rich epoxy anticorrosive coating(f-GO/ZRC)was prepared.The proportion of each component in the coating was determined by experiments The physical properties such as adhesion,hardness,impact strength and electrochemical properties such as open circuit potential,Tafel polarization curve and electrochemical impedance spectroscopy were tested.Finally,the salt spray resistance of the coating was tested and the anti-corrosion mechanism was analyzed.According to the properties of each component in the zinc-rich epoxy coating system and the selection of test material components,the optimal components are determined: epoxy resin E-44 and amine curing agent are film-forming polymers;800 mesh spherical zinc powder is added to the coating to improve the hardness and cathodic protection time of the coating;epoxy active diluent(PGE)improves the fluidity of E-44;thixotropic attapulgite improves the sagging resistance of the coating Properties and additives(defoamers,etc.).All the components were compounded.Through the orthogonal experiment,the optimum proportion of each component of zinc-rich epoxy coating is 18.5wt% E-44,18.5wt% amine curing agent,60.0wt% spherical zinc powder,2.0wt% epoxy active diluent and 1.0wt%attapulgite.Graphene oxide was modified by dopamine(DA)and silane coupling agent(APTES).The results show that compared with the unmodified graphene oxide,the DA-rGO modified by DA and APTES modified graphene oxide APTES-GO have better dispersion.DA-RGO and APTES-GO were characterized by FT-IR,XRD,Raman and SEM.The results showed that DA and APTES were successfully grafted onto the surface of graphene oxide.DA modified graphene oxide zinc-rich epoxy anticorrosive coating(DA-rGO)was successfully prepared by modifying graphene oxide with DA and adding it into zinc-rich epoxy coating.The physical properties of the coating show that the adhesion of the zinc-rich epoxy coating with 1wt% DArGO is grade 0 and the impact resistance is 50 cm.The electrochemical test results show that the zinc-rich epoxy coating with 1wt% DA-rGO has the longest cathodic protection time.The results of Tafel polarization curve and impedance spectrum show that the corrosion resistance of epoxy zinc rich coating with 1wt% DA-rGO is the best.Graphene oxide was modified by APTES and added to zinc-rich epoxy coating.APTES modified graphene oxide zinc-rich epoxy anticorrosive coating(AGO/ZRC)was successfully prepared.Through the analysis of physical properties,electrochemical properties and neutral salt spray test,it is concluded that the comprehensive performance of zinc-rich epoxy coating with 1.5wt% APTES-GO is the best.