Eco-Friendly Acrylate–Polyaniline Emulsion Coatings for Enhanced Corrosion Protection of Carbon Steel

This study presents the development of novel, environmentally friendly, waterborne coating blends based on acrylate emulsion incorporated with emulsified polyaniline (PANI) for the corrosion protection of mild steel. The coatings were prepared by emulsion blending with varying PANI contents (0–1.5 wt%) and evaluated through mechanical, electrochemical, and immersion-based tests. The addition of PANI improved the thermal stability, surface hardness, and corrosion resistance of the coatings due to increased interchain interactions and passivation effects. Electrochemical measurements revealed that the coating with 0.75 wt% PANI (CB0.75) exhibited the best performance, achieving a corrosion inhibition efficiency of 98.76% and the highest polarization resistance (10,157 Ω•cm²), while higher PANI loadings led to structural brittleness and reduced protective efficiency. These results highlight the importance of optimizing conductive polymer content and offer a promising route for scalable, VOC-free anticorrosion coatings for industrial and infrastructure applications.