Nanocomposite coating development based on natural rubber incorporated with graphene nanomaterials for corrosion protection

Graphene-reinforced epoxidised natural rubber–acrylic coatings were developed to enhance the corrosion protection of mild steel in chloride environments. Fourier transform infrared spectroscopy confirmed the preservation of key ester, urethane and epoxide functionalities upon graphene incorporation. Field emission scanning electron microscopy images showed that higher graphene loadings produced denser and more uniform surfaces, consistent with slight increases in water contact angle from 79.4° (ENR3/G0) to 87.3° (G10). Adhesion remained strong across all samples, with G6–G10 achieving 5B ratings. Differential scanning calorimetry revealed a shift in the first thermal degradation event from ∼185 °C (G2–G4) to ∼363–366 °C (G6–G10), indicating improved thermal stability. Electrochemical impedance spectroscopy demonstrated significant enhancement in corrosion resistance, with G6 and G10 maintaining impedance values of 10 8 –10 9 Ω·cm 2 after 30 days of immersion. These improvements arise from a combined mechanism involving a tortuous diffusion pathway, reduced defect density, strong polymer–graphene interactions and enhanced thermal robustness. Overall, graphene-reinforced epoxidised natural rubber–acrylic coatings show strong potential for long-term corrosion protection of mild steel.