Synthesis and Characterization of Waterborne Polyurethane Modified by Acrylate/nano-ZnO for Dyeing of Cotton Fabrics

Waterborne polyurethane modified by acrylate/nano-ZnO (PUA/ZnO) was synthesized and used to improve the wet rubbing fastness of reactive dyed cotton fabric. The reaction conditions were optimized and the products were characterized by FT-IR, TG, DSC, SEM, and particle size distribution. The dyed cotton fabrics were finished with PUA/ZnO emulsion and the rubbing fastness, ultraviolet resistant property, and wearability of treated fabrics were measured. The wet rubbing fastness of treated fabrics was increased by about 0.5–1 rate to achieve 3–4 rate, and the ultraviolet protection factor (UPF) achieved 50+ level. The whiteness, air permeability, and elongation at break of treated fabric were not decreased significantly. SEM showed that the smooth and reticular coating on the surface of treated fabric reduced the mechanical friction force between dyed fabric and rubbing cloth, and thus improved the rubbing fastness. The decomposition temperature of finished fabric was increased by 50–80 °C.