Self-Healing and Recyclable Fabric Coatings Based on Boroxine–Polyurethane

Fabric coatings, offering a range of benefits to personal health and the environment and addressing other specific needs, present a promising application in various fields. However, ensuring their long-term reliability, durability, and recyclability remains crucial to meet the demands of practical applications and sustainable development. To address this problem, we have developed a self-healing polyurethane (BPU) that integrates phenylboronic acid groups into the polyurethane chains and cross-links them to form dynamic boroxine bonds. This unique structure endows the BPU with a healing efficiency of 94%, a recycling efficiency of 93%, and an adhesion strength to cotton fabric of 1.42 MPa due to the high mobility of polymer chains and dynamic boroxine bonds. Leveraging these exceptional properties, we successfully prepared a multifunctional coating fabric (BPU/APD) by incorporating an azobenzene–polyurethane polymeric dye (APD) with BPU as a binder. This BPU/APD-coated fabric shows reversible photoisomeric behavior, remarkable ultraviolet protection function (UPF = 85.8), and excellent durability against washing and adhesion. Notably, the coated fabric can fully heal tiny scratches at 60 °C under 3 MPa for 5 min. After undergoing four healing cycles, the fractured coating fabric retains over 85% of its initial strength following the first healing, indicating its multiple healing capabilities. Moreover, the BPU/APD coatings on the waste fabrics can be recycled and reused repeatedly, maintaining a similar color strength and adhesion strength. This research paves the way for the development of multifunctional coating fabrics through the creation of self-healing polyurethane coatings, proving its great potential in smart textiles.