A Brief Communication on the Improved Mechanism of Graphene on Zinc-Rich Coatings

摘要

Gallic acid-based epoxy resin monomer was synthesized by the natural extract of gallnut for the efficientdispersion of graphene in epoxy resin. The graphene zinc-rich anticorrosion coatings were furtherprepared on the basis of the graphene / gallic acid-based epoxy resin monomer dispersion system.Electrochemical experiments and spectral characterization were carried out to study the effect ofgraphene on zinc-rich coatings and its mechanism. Experiments showed that graphene enhanced thecathodic protection currents of the zinc-rich coatings and prolonged the cathodic protection time.Simultaneously, graphene slowed down the penetration of corrosive media into the coatings. Theconductivity of graphene improved electrical contact between zinc particles as well as zinc and iron, andtransformed un-activated zinc particles into activated zinc particles. The dispersed and layered structureof the graphene extended the permeation path of the corrosive medium, which resulted in reducedpermeation rate and decreased water content of the coatings. It was demonstrated by the tracking of zinccorrosion products by micro-area Raman spectroscopy.