| Graphene(GR),as a two-dimensional lamellar nano-material,has a large specific surface area,excellent chemical stability,superconductivity,small size,wear resistance and heat resistance.Therefore,GR can be used in the field of anticorrosive coatings.It can make up for the defects of coatings by using small size characteristics,and form a compact physical barrier layer,thereby enhancing the corrosion resistance of coatings.At present,some studies have applied graphene to anticorrosive coatings,so that the physical properties or anticorrosive properties of coatings have been significantly improved,but it can not achieve the effect of heavy anticorrosive,and can not withstand more severe environment for a long time.Therefore,finding the basic formula of graphene heavy anticorrosive coatings to achieve the degree of heavy anticorrosive is the focus of this study.On the basis of the existing graphene coating system and epoxy resin(EP)heavy-duty anticorrosive coating system formulation,the test conditions such as the content of each component of the coating were optimized to further iruprove the anticorrosive performance of the anticorrosive coating in order to prepare graphene heavy-duty anticorrosive coating.The effects of the important components of the coating on the properties of the coating were studied by single factor test,including:pigments and fillers(varieties,dosage,mixing ratio),curing agent dosage,graphene(dosage,modification),solvent ratio,etc.The mechanical properties,scanning electron microscopy(SEM)test and AC impedance test showed that titanium dioxide was more suitable as a single pigment and filler,and the coating mechanics was determined when the dosage was 4.5g.The results show that the performance of the coatings is better when the ratio of titanium dioxide to mica powder is 1:1,the impedance value of the coatings is higher when the ratio of titanium dioxide to mica powder is 1:1,the curing effect is better when the curing agent(651)is 1.5g(30%of EP),and the mechanical properties are stronger;when the content of graphene is 0.05g,the comprehensive performance of the coatings is better(1%of EP),the coupling agent KH550 alone is not ideal for the modification of graphene.Hollow glass microspheres(HGM)can effectively improve the dispersion of graphene.When HGM/GR is 2:13,the impedance value of the coating is higher;when the ratio of n-butanol to toluene is 1:3,the impedance value of the coating is higher.Based on the results of single factor test,three kinds of admixtures were selected as horizontal orthogonal experiments,and the AC impedance analysis and range variance calculation of the samples were carried out,respectively,with the content of pigments and fillers,graphene and curing agent as the factors.The main and secondary factors are the content of pigments and fillers,the amount of graphene,the amount of curing agent,the optimized group is 4 g of pigment filler,2.5 g of curing agent and 0.1 g of graphene.On the basis of the above,orthogonal design is made for the proportion of mixed filler,the proportion of mixed solvent and the proportion of HGM/GR,and the AC impedance test is made for the sample,and the range and variance are calculated.The results show that the primary and secondary factors are the proportion of filler,the proportion of solvent,and the modified filler.The ratio of HGM to GR is 3:7,the ratio of titanium dioxide to miea is 1:2,and the ratio of n-butanol to toluene is 3:7.The graphene anticorrosive coating prepared according to the optimized formulation accords with the national standard of heavy anticorrosive coating. |
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