Sustainable photothermal-responsive anti-corrosion nanocomposite coating with distinguished self-healing performance and ultrahigh mechanical properties

Abstract

Intelligent self-healing corrosion protection materials with photothermal-responsive performance have become a research hotspot with the gradual attention of people to the problem of corrosion of metal materials, while it is still challenging to impart simultaneously exceptional self-healing abilities and ultrahigh mechanical capabilities to materials. Herein, the dynamic bonds including hydrogen and oxime urethane bonds were introduced to the bio-based polyurethane (PU) by using photothermal-responsive chain extender 1,4-benzoquinone dioxime (QDO) and bio-based chain extender 2,5-tetrahydrofurandimethanol (THFDM), ecologically friendly halloysite nanotube modified by ferric ion and tannic acid (TA/Fe³⁺@HNT) was further incorporated to the PU polymer to form abundant interfacial hydrogen bonds. The nanocomposite material possesses strong tensile strength (64.4 MPa), distinguished toughness (785.5 MJ m⁻³), and efficient self-repairing properties (92.0 %, healing for 24 h at 35 °C). Moreover, the temperature of the material rises rapidly to 100.2 °C after irradiating for 90 s under near-infrared (NIR) light, which imparts shape memory properties and a more efficient self-healing performance (98.2 %, irradiating for 30 min) to the material. Meanwhile, the high coating's impedance modulus at 0.01 Hz (4.25 × 10⁸ Ω cm²) in 3.5 wt% NaCl solution with 45 days of soaking demonstrates its excellent long-lasting corrosive resistance. Hence, our work provides a straightforward and feasible method to fabricate high-performing photothermal-responsive self-healing PU nanocomposite that can be applied to long-term corrosion protection of metal materials.