Environmentally friendly non-isocyanate polyurethane binder for pigment dyeing

Non-isocyanate polyurethanes have rapidly risen as an environmentally friendly substitute to traditional isocyanate-based polyurethanes. Here, a crosslinked non-isocyanate polyurethane (CNIPU) was prepared with cyclic carbonate, polyamine, and diglycidyl ether via simple ring-opening and transcarbamoylation methods. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirm the successful preparation of CNIPU. When the CNIPU is used as the pigment-dyeing binder for cotton fabric, the thermochromic microcapsules can be fixed on the fiber surface. The dyed fabric shows excellent thermochromic property and its color fastness can reach above 4 grade. This work offers an efficient strategy to utilize non-isocyanate polyurethane to fabricate pigment-dyed fabrics with green and sustainable route. Graphical abstract Synthesis of a crosslinked non-isocyanate polyurethane binder and its application in pigment dyeing.