Photothermal Self‐Healing Waterborne Polyurethane with Antibacterial, Hydrophobic, and Oleophobic Properties Based on Dynamic Hindered Urea Bonds

ABSTRACT To endow polyurethane coating with photothermal self‐healing, antibacterial, hydrophobic, and oleophobic properties, in this study, cellulose nanofiber coated with polydopamine and silver nanoparticles (CNF@PDA@AgNPs) and hindered urea bonds were introduced into fluorinated waterborne polyurethane as functional nanofillers and dynamic motifs, respectively. Owing to the remarkable photothermal property of CNF@PDA@AgNPs and the presence of dynamic hindered urea bonds, the photothermal self‐healing fluorinated waterborne polyurethane urea (PSF‐WPU) film exhibited excellent self‐healing capability. Under a xenon lamp irradiation with an intensity of 100 mW/cm 2 for 4 h, the self‐healing efficiency of its tensile strength and elongation at break reached 95.20% and 95.19% of its original properties, respectively. With the increase of CNF@PDA@AgNPs dosage, the water‐oil contact angles of the PSF‐WPU film increased. Furthermore, silver nanoparticles (AgNPs) as antibacterial agents endowed PSF‐WPU finished fabrics with excellent antibacterial properties, with 99.37% and 90.29% against E. coli and S. aureus , respectively. This work offers a feasible approach for fabricating self‐healing waterborne polyurethanes with outstanding photothermal antibacterial, mechanical, hydrophobic, and oleophobic performances that have great potential in the areas of coatings, textiles, leather, and biomedicine.