Cartilage-Inspiration for Constructing Photothermal-Driven, Weather-Resistant, Self-Healing and Long-Term Anti-Corrosion Dual-Layer Coating

Abstract

The economic and social damages caused by steel corrosion are enormous, and the development of efficient and long-term anti-corrosion coatings has become a key challenge. The aim of this study was to develop a novel, photothermal self-repairing, intelligent, weather resistance, and anti-corrosion composite coating. In this study, cartilage-inspired tannic acid (TA)-modified MXene multifunctional filler (MT) was prepared by a hydrothermal method and combined with self-repairing polyurethane (PU-SS-Salen-Ni) to form a topcoat, while epoxy resin (901) was selected as the primer. The network structure of MT endowed the polyurethane with highly efficient photo-thermal conversion ability, which could increase the local temperature of the material to more than 80°C within 60s. It also gives the coating excellent weathering resistance. Thanks to the synergistic effect of the active anticorrosive properties of MXene, the passive anticorrosive effect of tannic acid, and the self-healing polyurethane epoxy double-layer coating on the substrate, the composites exhibited excellent anticorrosive properties (|Z|f=0.01Hz >1 × 1011 Ω·cm²) after 180 days of immersion in 3.5% NaCl solution. Therefore, the present work successfully realized polyurethane materials with active/passive corrosion protection and self-healing functions through MT networks, and innovatively introduced and studied the organic double-layer coating structure, which provides a new solution in the field of corrosion prevention, weathering, and photo-thermal conversion self-healing.

Keywords: MXene, Photothermal self-healing, Polyurethane, Anti-corrosion coating, cartilage