Lignin self-healing coatings based on thermo-reversible Diels-Alder reaction for anticorrosion applications

In the current research, we explored the fabrication of thermo-reversible polymer networks made of bio-based materials to address the growing need for greener and more sustainable polymer coating. Herein, we developed thermally self-healing lignin-based coatings with strong anticorrosion performances through Diels-Alder crosslinking strategy. Accordingly, organosolv lignin was first functionalized by furan moieties and then used for thermally crosslinking by 4,4′-bismaleimidodiphenylmethane (BMI) after spin casting on the surface of steel sheets. Under the optimum conditions, the obtained coating could generate smooth and defect free layers. A thin layer (18 μm) of this coating could increase the Ecorr from −481 mV (for bare steel) to +142 mV and reduced the corrosion rate (CR) over 3300 times. Importantly, the thermo-reversibility of the network endows excellent self-healing ability to the coating. Indeed, lignin self-healing coatings based on thermo-reversible Diels-Alder reaction provides a creative strategy for bio-based materials applied in anticorrosion applications with high-performance.