Preparation And Properties Study Of Self-healing Anti-corrosion Coating With MCM-41 As Nanocontainer

Organic coating is a common method for corrosion protection of metal surfaces.However,traditional organic coatings are prone to form defects and cracks in the process of usage,which significantly reduces the shielding of the coating.Therefore,in order to extend the service life of the coating and avoid local corrosion of the metal substrate,the anti-corrosive coating with self-healing function has been studied.When the coating is damaged or corroded,self-healing coatings are intelligent protective materials that can self-repair the damages caused in service.In this paper,MCM-41 was selected as a nanocontainer for loading triazine corrosion inhibitors,and a self-healing organic anti-corrosion coating was prepared by layer-by-layer self-assembly method,which was applied to the corrosion protection of Q235 carbon steel.The main research contents of this paper are as follows:1.The mesoporous molecular sieve(MS)was added to the epoxy resin E-44(EP)through high-speed dispersion,and the MS-EP coating was obtained.Electrochemical impedance spectroscopy test,potentiodynamic polarization curve test and salt spray test were used to explore the influence of the amount of MS on the anti-corrosion performance of the MS-EP coating,and the mechanical properties of MS-EP coatings were examined.2.The triazine-based corrosion inhibitor(Inh)was loaded into the MS cavity(Inh@MS)by vacuum impregnation.Then,the Inh@MS was added to the epoxy resin to obtain Inh@MS-EP coating.The Fourier transform infrared spectroscopy(FT-IR)method and BET specific surface area test confirmed that Inh had been successfully loaded into MS.Thermogravimetric test(TG)determined the loading amount of Inh.Electrochemical impedance spectroscopy test,Potentiodynamic polarization curve test and salt spray test were used to explore the effect of the amount of Inh@MS on the anti-corrosion performance of the Inh@MS-EP coating,and the mechanical properties of Inh@MS-EP coatings were also exzmined.3.In order to further improve the anti-corrosion ability of the coating,an anti-corrosion material with self-healing function was prepared.The surface of the Inh@MS was coated with polyethyleneimine(PEI)and sodium polystyrene sulfonate(PSS)by layer-by-layer self-assembly technology,and a self-healing microcapsule Inh@MS/PEI/PSS with p H response function was constructed.The Inh@MS/PEI/PSS-EP coating with self-healing function was obtained by adding Inh@MS/PEI/PSS to the epoxy resin.The coating exhibits excellent self-healing anti-corrosion properties for Q235 steel in 3.5 wt.% Na Cl solution.When corrosion occurs on the surface of the substrate,the p H changes caused by corrosion stimulates the release of Inh molecules from Inh@MS/PEI/PSS,and the released Inh molecules can be adsorbed on the surface of the substrate to form a film,thereby effectively inhibiting the further corrosion of the carbon steel matrix,giving the coating self-healing function and improving the anti-corrosion performance of the coating.