Environmentally Friendly Waterborne Polymer/Reduced Graphene Oxide Nanocomposite Anticorrosion Coatings for Q235 Carbon Steel

ABSTRACT Corrosion severely affects marine metallic infrastructures. Organic coatings offer a low‐cost, effective solution, but their solvent‐rich processing reduces sustainability. For polymer nanocomposite coatings, additional chemical modification of fillers is typically required to improve dispersibility. Herein, we report the synthesis of waterborne polymer/reduced graphene oxide (rGO) nanocomposites via a miniemulsion polymerization as an anticorrosion coating for Q235 steel. Using a vinyl copolymer based on styrene and n ‐butyl acrylate, we successfully formulated kinetically stable latexes with inherent film‐forming ability at room temperature. The thermally annealed polymer/rGO coatings formed a uniform, defect‐free layer on the steel surface without rGO agglomeration and delamination. These polymer/rGO coatings, particularly at pH 10 demonstrated electrical conductivity, mechanical robustness, and highly effective anticorrosion performance. Polymer/rGO coating of pH 10 exhibited enhanced corrosion protection after 168 h exposure to 3.5 wt.% NaCl solution (( I corr = 0.01 µA cm −2 , P.E of 99%), outperforming the corresponding pH 2, neat polymer coating, and bare metal, validated by post‐immersion analysis and marine field testing. This organic solvent‐free type of protective coating, comprising vinyl polymer and unmodified rGO represents a novel approach towards the development of advanced anticorrosion coating for critical metals.