Near-infrared radiation and heat dual-induced self-healing polyurethane with anti-abrasion ability

Disulfide bonds are widely used in self-healing materials owing to their dynamic nature under mild conditions. However, their practical application is severely limited by their low tensile strength. In this work, a linear polyurethane (CHPU) containing disulfide bonds and crystalline polycaprolactone diol is designed and synthesized. The infiltration of polypyrrole (PPy) nanoparticles endows the CHPU/0.5PPy nanocomposites with a high tensile strength (26.23 MPa), high toughness (119.71 MJ/m3), and a remote self-healing ability that can be triggered by heat or low-intensity (near-infrared) NIR radiation. A cut CHPU/0.5PPy film can recover 77.35% and 64.77% of its original tensile strength under 808 nm NIR radiation (118.46 mW/cm2) and 50 °C, respectively. In addition, CHPU/0.5PPy can bear 300 reciprocating linear abrasion cycles (0.5 N load force) with a stable friction coefficient, delivering a performance superior to those of many commercial anti-abrasion polyurethane coatings.