Synergistic Effect of Electrocatalytic Characteristics of a Redox Segment and Gas Barrier of rGO to Significantly Replace the Loading of Zinc Dust in Solvent-Based Epoxy Composites Applied for Heavy-Duty Anticorrosion Coatings

Abstract

Zinc-rich epoxy coating plays a major role in current heavy-duty corrosion protection solutions, yet high loading of zinc dust (ZD) weakens the coating flexibility and adhesion capability of the overall coating. This work demonstrated the successful incorporation of small amounts of rGO and aniline pentamer (AP)-based diamine into zinc-rich non-electroactive epoxy thermoset (NEET) as a novel heavy-duty anticorrosion coating composite. This coating composite promoted its wear resistance without sacrificing anticorrosion performance and adhesion ability while effectively reducing the loading of ZD. Based on a series of electrochemical measurements, an electroactive epoxy thermoset (EET) containing 5 wt % electroactive AP-based diamine (DAAP) and 0.5 wt % rGO can replace 70 wt % ZD and shows equivalent anticorrosion performance under an accelerated salt-spray assay and electrochemical corrosion measurements. Furthermore, coatings containing DAAP and rGO exhibited improved wear resistance and good adhesion capability.