Study On Anticorrosion Performance Of Attapulgite Crosslinked Graphene Synergistic Organic Coating

The corrosion of metal materials during service is an unavoidable phenomenon that can be mitigated as much as possible.In order to reduce the safety hazards and economic losses caused by metal corrosion,a common method is to apply an organic coating on the metal surface for protection.In recent years,with the continuous strengthening of green and environmental protection requirements,the demand for green organic anti-corrosion coatings is increasing.For example,Sol-gel coatings have good adhesion on the surface of metal substrates,and waterborne epoxy resin coating Non-toxic,wide range of applications and other advantages,but their anti-corrosion performance is not ideal.In this paper,firstly,the technical route of graphene and graphene oxide prepared from graphite was optimized.After that,the graphene products and attapulgite were crosslinked and grafted with silane precursor to form the composite nano flake with attapulgite crosslinked on the surface of graphene flake.Then,the graphene composite nanosheets were used to modify the Sol-gel coating and waterborne epoxy coating respectively,resulting in a high performance organic anti-corrosion coating.The main research contents and results are as follows:1.The preparation process of graphene by mechanical ball milling was studied.Thiourea as ball milling agent can improve the stripping efficiency of graphite and produce graphene monolayer efficiently.The results show that the graphene monolayer can be peeled off and the monolayer is relatively complete.Through the optimization and improvement of some processes of graphene oxide prepared by Hummers method,the oxidation time of graphite was increased at room temperature,and then the dangerous stage of high temperature was cancelled.High quality graphene oxide flakes were obtained.The graphene oxide film is thin and has a large number of oxygen-containing groups.2.Attapulgite graphene(GNS-ATP)nanocomposites were prepared.Firstly,graphene was grafted by Attapulgite via TEOS as precursor to prepare graphene film coated by attapulgite.Then,the corrosion resistance of graphene as a Sol-gel filler before and after modification was evaluated.The results show that the insulation of graphene is increased and the micro galvanic effect of graphene is reduced.Thus,the diffusion path length and diffusion time of corrosive ions can be increased by virtue of the shielding property of graphene itself.Therefore,the corrosion protection of the coating can be improved.3.Attapulgite graphene oxide(GO-ATP)nanocomposites were prepared.It was used as a filler to modify the coating of water-based E51 resin,so as to prepare attapulgite graphene oxide / water-based epoxy composite coating.Based on the characterization and analysis of the structure of the composite nano sheet,the corrosion resistance of the composite coating was further studied.The corrosion protection mechanism of the modified coating was discussed.The results show that the dispersion stability of graphene oxide nanoflakes in waterborne epoxy coating can be improved significantly after grafting with attapulgite.Attapulgite graphene oxide nanocomposites can significantly improve the corrosion resistance of waterborne epoxy coating,and its improvement effect is better than that of single graphene oxide.The enhancement effect is mainly due to the synergistic barrier between attapulgite nanofibers and graphene oxide nanosheets.