Intelligent anti-corrosion coating with self-healing capability and superior mechanical properties

Intelligent anti-corrosion coatings with self-healing capabilities and enhanced mechanical properties are essential for prolonging the service life of substrate materials. While extensive research has been conducted on coatings with single functions, there remains significant potential for studies that integrate both functionalities simultaneously. In this study, a self-healing anti-corrosion polyurethane composite coating (TM/PU) was developed by doping it with TO@CA microcapsules (tung oil calcium alginate, TO@CA) and multi-walled carbon nanotubes (MWCNTs). The experimental results demonstrated that the tensile strength of the composite coating T₂M₂/PU, containing 0.5 wt% TO@CA and 0.1 wt% MWCNTs, was 46.72% higher than that of the pure PU coating, while its adhesion strength increased by 123.20%. Moreover, MWCNTs played a crucial role in intelligently directing the distribution and diffusion of restorative agents within the coating. The T₂M₂/PU coating exhibited corrosion resistance for up to 648 h and achieved a self-healing rate of 91.7%, which is 243.45% higher than that of the pure PU coating, thereby enabling rapid repair. This study successfully integrated intelligent self-healing mechanisms with the enhancement of mechanical properties in coatings, offering a novel perspective for the corrosion protection of marine equipment structures and aerospace components.