Preparation Of Modified Graphene/polyaniline Composites And Study On Anti-corrosive Properties Of Its Coatings

In order to improve the hole defect of epoxy resin anti-corrosive coating,graphene and polyaniline can be used as fillers to improve the anti-corrosive performance of epoxy coating.Graphene has excellent mechanical strength,outstanding barrier property,and high thermal conductivity,but it is easy to agglomerate.Polyaniline has good electrical conductivity and unique anti-corrosive properties,but is not easily dispersed in solvents.It is limited to improve the anti-corrosive properties of the coatings when they are added as functional fillers alone.This is due to the defect in the performance of graphene and polyaniline itself.In order to overcome the defect of graphene and polyaniline,a modified graphene/polyaniline composite material covalently grafted can be prepared.In this paper,graphene oxide(GO)was prepared by modified Hummers method,and modified graphene(PGO)was prepared by reducing GO with p-phenylenediamine,further modified graphene/polyaniline composites(PGO/PANI)were prepared,and the corrosive resistance of the coatings was analyzed.From the structural analysis of GO,PGO and PGO/PANI composites,it was found that p-phenylenediamine also reduced GO at the same time as modified GO,and PGO and PANI grafted successfully.The PGO prepared in the form of single layer or several layers by electron microscopy,and PANI nanorods can grow on the surface of PGO to form PGO/PANI composites.The prepared PGO/PANI composite material was used as a functional filler and added to the epoxy resin to prepare a coating.the addition of functional filler PGO/PANI composites,the level of adhesion of the coating was increased from 3 grades of pure epoxy resin coating to 1 grade,the corrosive grade was improved from 6 grades to 0 grade,and the appearance grade was improved from 6 grades to 8 grades;The Tafel curve shows that the corrosive voltage of the composite coating is-194.59 m V,the corrosive current is 2.12×10-9A/cm2,the electrical resistance is 3078.62KΩ·cm2,and the corrosive protection efficiency is 99.99%;Through electrochemical impedance spectroscopy(EIS),it is concluded that PGO and PANI have a good synergistic effect.When PGO mass accounts for 10% of PANI mass,theanti-corrosive effect increases by 2 orders of magnitude.