Functional Modification Of Graphene Oxide And Its Application In Anti-corrosion Coatings

Corrosion can be seen in everywhere.With the development of economy in our country,the problem caused by corrosion has been paid more and more attention in recent years.To prevent the corrosion is imminent since the serious corrosion has caused significant economic losses.The application of anti-corrosion coatings is an important measure to reduce the surface corrosion of materials,so it has been widely studied.While graphene is a new carbon material which is composed of a single layer of carbon atoms tightly packed into,with excellent conductivity,thermal stability,mechanical properties and shielding effect.Especially its unique lamellar structure with high anti permeability for gas molecules,so it can be used as a functional filler to improve the anticorrosive performance of the coatings.In this paper,graphene oxide(GO)was prepared by modified Hummers method,then reduced by hydrothermal reduction method with hydrazine hydrate and received reduced graphene oxide(rGO),and rGO can be used as an additive to polyvinyl butyral(PVB)coatings.The coatings with different content of rGO(0.1 wt%,0.3 wt%,0.6 wt%)were prepared by brushing method,Tafel polarization curves and immersion test were used to investigated the anticorrosive performance of the coatings.The results showed that in the study area,the anti-corrosion performance of the coating was improved with the increase of the amount of rGO.It was investigated that when the amount of rGO was 0.6 wt%,the anticorrosion performance was the best,which proves that rGO can increase the compactness of the anticorrosion coatings,and the rapid conductivity can effectively improve the anticorrosion performance of the coatings.Modified graphene oxide(P-GO)was prepared by functionalization of GO with small molecules of p-phenylenediamine(PPD),refluxing at 95 ?.Furthermore,the obtained P-GO was applied in the PVB anticorrosion coatings as filler.The results showed that the higher thermostability of P-GO representing the partial reduction during modification.It was investigated that with the increase of P-GO content,the anticorrosion performance of the coatings increased firstly and then decreased,and there was an optimum value.When the amount of P-GO was 0.8 wt%,the performance of the coating was excellent.The modified GO can improve the performance of coatings effectively with its good dispersion,unique two-dimensional lamellar structure and shielding effect.Polyaniline(PANI)has excellent electrical conductivity and easily to be oxidation reduction.The mixture of P-GO and PANI in a certain proportion(3:1,1:1,1:3,0:1)was added as anticorrosion filler into the PVB anticorrosive coatings to investigated how the mixture affect the performance of the coatings.The results showed that when P-GO:PANI=1:3,the anticorrosion performance of the coatings was better.