Synthesis of silicone-modified self-healing polyurethane coatings with MXene@fluorinated polyaniline for prolonged corrosion resistance

Abstract

Numerous synergistic anticorrosion methods have attracted great research interest. A silicone-modified self-healing polyurethane composite coating, known as MXene@ fluorinated polyaniline, was synthesized through in situ polymerization of fluorinated polyaniline on the MXene surface using polydopamine to enhance the compatibility between the filler and the polyurethane coating. The anticorrosion efficiency of the coating was examined in a 3.5 wt% NaCl solution via electrochemical impedance spectroscopy. The synergistic effect of polyaniline passivation and the physical barrier effect of MXene indicated that even after 100 d of immersion, the impedance modulus of the composite coating at 0.01 Hz remained above 10⁸ Ω·cm². Additionally, the introduction of disulfide linkages into the coating endowed it with self-healing properties. Owing to the superior photothermal capabilities of MXene, polyaniline, and polydopamine, the polyurethane coating exhibited self-healing abilities in the presence of sunlight. The coating retained its mechanical and anticorrosion properties both before and after the self-healing process. This approach integrates the synergistic effects of MXene, polyaniline, and dynamic disulfide bonds to meet the requirements of coatings in harsh environments, thereby prolonging the lifespan of metals.