Preparation Of Modified Graphene Oxide And Its Application In Polymer Anticorrosive Coatings

As one of the most important structural materials,carbon steel is used in almost the entire industrial field with its excellent properties.However,severe corrosion of carbon steel often leads to numerous hidden safety hazards and huge economic losses.Now water-based epoxy resins have begun to be widely used as adhesives and coatings.However,the water-based epoxy resin will produce a large number of micropores during the curing process,causing the external corrosive medium to rapidly penetrate into the protective substrate,which severely limits the application of the water-based epoxy resin in the industry.So far,a more effective way to solve this problem is to use micro-nano fillers in the coating to effectively prevent the micropores of the coating due to the evaporation of water.For this reason,adding nanoparticles to water-based epoxy resins to improve the corrosion resistance of coatings has been extensively studied.Previous studies have shown that water-based epoxy resin composites have good corrosion resistance,especially composite materials containing layered micro-nano fillers.Due to its unique characteristics,graphene can prevent oxygen and water molecules from diffusing to the surface of metal-based materials,thereby protecting the metal from oxidative corrosion.Graphene and its derivatives have been successfully used as preservatives to improve the coating's performance.Corrosion resistance,however,the water dispersibility of graphene derivatives is still a challenge,which seriously affects its application in anti-corrosion.The surface chemical modification of GO with functional groups promotes the functionalized GO in the polymer matrix.Disperse evenly.Based on the modification of GO,this experiment provides three solutions to improve the water dispersibility of GO and the anti-corrosion performance of waterborne epoxy resin.The specific experiment content and results are summarized as follows:The first chapter of this article first explains the hazards of metal corrosion and the universality of coating protection,and then focuses on graphene and graphene oxide and their modification methods and anti-corrosion ideas,and summarizes epoxy resin and water-based epoxy resin.Finally,several preparation methods of nanomaterials and polymer composite materials are summarized.In the second chapter of this article,ai ming at the problem of poor GO dispersion,a PG composite material was prepared using a large amount of a mine functionalized graphene oxide on polyethylenei mine,and the prepared PG material was added to the water-based epoxy resin.The results showed that the prepared PG composite material can be stably dispersed in water-based epoxy resin,and when the mass fraction of PG is 0.5 wt%,the anti-corrosion efficiency of the composite coating can reach 99.76%.At the same time,considering the a mine groups on the polyethylenei mine and the sharp edges of the graphene oxide nanosheets,a PG modified waterborne polyurethane(PGWPU)composite was prepared by a blending method,and the effect of PG content on the antibacterial rate was studied.The results showed that when the content of PG was 0.2 wt%,the antibacterial rate of the film against Escherichia coli was 99.9%,and it had an excellent antibacterial effect.The third chapter of this paper uses chlorosulfonic acid,aniline and ammonium persulfate as the main raw materials to synthesize sulfonated polyaniline,and uses the active sites on GO to combine with the prepared PG composite material.The strong?-?^*interaction between PG and SPANI makes the obtained SPG composite material more s Tab and greatly increases the dispersion of GO in the aqueous solution,so that the composite material has excellent anti-corrosion properties.The product was analyzed for water dispersibility and solubility test,and it was found that the product obtained can stand in the environment for one month without precipitation,and the solubility of the product in water after testing can reach 15.8 mg·mL^-1.Through salt spray test and electrochemical test,it is found that when the mass fraction of SPG is2.5 wt%,the SPG/EP composite has excellent corrosion resistance,and the corrosion efficiency can reach 99.19%.In the fourth chapter of this paper,combining the coating properties of cyclodextrin and the impermeability properties of graphene oxide nanosheets,a new type of polyethylenei mine modified graphene oxide/cyclodextrin nanocontainer was developed to achieve self-repairing water-based Epoxy coating.Characterization of the obtained product by FTIR and XRD showed that the composite material PGCd-MBT was successfully prepared.In addition,TG results and DSC results show that the addition of composite materials improves the thermal stability of the coating,and the prepared container has a higher corrosion inhibitor carrying capacity.Subsequently,a release experiment proved that the prepared nanocontainer has a p H-responsive release,which can be quickly released when the coating is damaged,effectively preventing further corrosion.The salt spray test further embodies the corrosion resistance of the composite coating apparently,and the electrochemical data theoretically confirms that the addition of the composite material PGCd-MBT can improve the anticorrosion effect of the coating.When the content of PGCd-MBT reaches 5 wt%,the corrosion efficiency can reach 99.96%,which has great potential in actual anti-corrosion applications.