Considering the effect of graphene loading in water-based epoxy coatings

Abstract

Recently, graphene has gained increasing interest in numerous fields of application and, in particular, it has been used as a nanofiller in the preparation of polymeric composites to improve their mechanical and transport properties. However, the effect of graphene as a potential additive for anticorrosive organic coatings is not widely studied. In this work, low levels of graphene nanosheets, 0.5 and 1 wt%, were added to an additive-free waterborne epoxy resin applied to Al2024-T3 aluminum alloy samples. The presence of graphene did not affect the polymerization process of the resin and the adhesion at coating/substrate interface, as demonstrated by experimental results, while showing a slight effect on coatings wettability. Electrochemical analysis revealed an improvement of the protective properties of the coating that could be assigned to a slow absorption rate of the electrolytes in the polymeric matrix and a lesser amount of absorbed water than the unloaded film.