Preparation and properties of self-healing photochromic polyurethane composite fabric

In order to improve the durability of photochromic coated fabrics, the photochromic microcapsules (PM) and zwitterionic polyurethane (ZPU) were used to prepare PM/ZPU films, which were then hot-pressed onto cotton fabrics to obtain the self-healing PM/ZPU composite fabrics. The structure and morphology of PM/ZPU composite fabric were characterized, and the photochromic properties, self-healing and recycling ability of PM/ZPU composite fabric were discussed in detail. The results show that the maximum absorption wavelength of PM/ZPU composite fabric changes from 470 nm to 530 nm, the color changes from yellow-orange to reddish-brown, and the fabric has good fatigue resistance. Based on the dynamic reversibility of zwitterionic, the scratches of PM/ZPU composite fabric can be completely repaired at 80℃, and the bond strength of the fractured composite fabric reaches 1.47 MPa at 60℃, showing excellent self-healing properties. The coating on the waste fabric can be recycled and reused by a simple dissolution method, and the PM/ZPU composite fabric can still be prepared with good photochromic properties.