Advances and perspectives in organic inhibitor-based anti-corrosion coatings: Biodegradable polymers, natural extracts, and synthetic compounds

This review focuses on progress and advances in the preparation of anti-corrosion coatings using organic inhibitors. It looks at examples of biodegradable polymers, plant extracts, and synthetic organic compounds, revealing interesting results and offering new perspectives on their potential applications. The review provides both experimental and theoretical evidence of the high corrosion inhibitory properties of carbon steels and alloys in acidic and saline environments. Chitosan derivatives with chemical modifications, such as Schiff bases and nanocomposites, can achieve significant efficiencies in producing stable protective coatings through physical and chemical adsorption. The environmentally friendly approach of using flavonoids, phenols and alkaloids from plant or agricultural residue extracts to achieve up to significant values inhibition is also introduced. Furthermore, the review discusses synthetic organic compounds and ionic liquids acting as mixed inhibitors, with detailed adsorption mechanisms reported by quantum chemistry analysis and molecular simulations. Finally, the addition of inhibitors and additives, provides synergistic corrosion protection. Organic inhibitors offer a sustainable and effective means of protecting metals in aggressive environments.