| Graphene has the advantages of high aspect ratio,large specific surface area and hydrophobicity,which is beneficial to prolong the permeation path of corrosive medium and improve the shielding of gases.However,graphene is very easy to agglomerate due to its inherent van der Waals force,which limits its application in organic anticorrosive coatings.In addition,mechanical damage in the application of anti-corrosion coatings is also an important reason hindering its anti-corrosion effect.Therefore,in order to further enhance the anti-corrosion effect of graphene in anti-corrosion coatings,organic polymers and inorganic nano-oxides are used to modify graphene and used as a corrosion-inhibiting container,which is compounded with epoxy modified polyurethane resin,aiming to develop a high-quality anti-corrosion coating with excellent physical barrier properties and self-repairing performance.Polyvinyl alcohol（PVA）was used to modify graphene oxide,and hexamethyl diisocyanate（HDI）was used as a crosslinking agent to prepare polyvinyl alcohol modified graphene loaded with cerium hydroxide（r GPHC）.The material not only improves the dispersibility of graphene,but also increases the loading sites of cerium hydroxide.r GPHC was used as a filler to compound with epoxy modified polyurethane resin（EP-PU）,and the optimal ratio of the composite coating is studied.The anti-corrosion performance of the material is studied through electrochemical test.Polarization test results show that the corrosion rate of Q235 mild steel in r GPHC dispersion is 67.87%lower than that of blank mild steel.The impedance test shows that the 0.25%r GPHC/EP-PU coating has the best anti-corrosion performance,and the|Z|10 m Hzof the coating is about 2 orders of magnitude higher than that of the pure EP-PU coating;the|Z|10m Hz of scratched 0.25%r GPHC/EP-PU coating is 3.10 times that of the pure EP-PU coating,showing excellent barrier properties and self-repairing properties.Polyethyleneimine（PEI）was used to modify graphene oxide to prepare graphene-based corrosion inhibitor loaded with zinc phosphate（r GPZ）.The grafting of PEI on the surface of graphene significantly reduces the agglomeration of graphene.It is found that the r GPZ/EP-PU coating has excellent anti-corrosion effects by comparing with the blank resin and the resin coating with GO,r GO,r GZ,r GPZ embedded respectively.Polarization test results show that the corrosion rate of Q235 mild steel in r GPZ dispersion is 64.60%lower than that of blank mild steel.The impedance test shows that the|Z|10 m Hz of the r GPZ/EP-PU composite coating is higher than the other three composite coatings and the pure EP-PU coating,among them,it is1 orders of magnitude higher than pure EP-PU coating;the|Z|10 m Hz of scratched r GPZ/EP-PU coating is 3.47 times that of the pure EP-PU coating,showing excellent barrier properties and self-repairing properties.The hollow mesoporous silica modified graphene oxide was prepared by the sacrificial template method,then alkyl-modified and amino-modified silica-modified graphene loaded with benzotriazole（r GSHB and r GSAB）were obtained by further modification of hexadecyltrimethoxysilane and 3-aminopropyltriethoxysilane respectively.The polarization test results show that the corrosion rate of Q235 mild steel in r GSHB and r GSAB dispersions is 85.22%and 87.95%lower than that of blank mild steel respectively.The impedance test further shows that both r GSHB/EP-PU coating and r GSAB/EP-PU coating have outstanding anti-corrosion effects,and its|Z|10 m Hz is 2 orders of magnitude higher than that of the pure EP-PU coating;the|Z|10 m Hz of scratched r GSHB/EP-PU coating and r GSAB/EP-PU coating are1.87 and 2.10 times that of pure EP-PU coating respectively,showing excellent barrier properties and self-repairing properties. |
