Preparation and properties of end-group cross-linked organosilicon modified waterborne polyurethane for digital inkjet dyeing of polyester without washing

Disperse dyes wash-free inkjet-dyeing is one of the important research and development directions to achieve clean dyeing of polyester fabrics. Wash-free binders are needed to be designed with a special molecular structure to achieve good colour yield and fixation during dyeing. Specifically, isophorone diisocyanate and polypropylene glycol were used as the monomers of the hard and soft chain segments of the polymer, respectively, and KH-560 as the capping agent, to prepare a series of end-group cross-linked organosilicon modified waterborne polyurethane (SWPU). It was applied as wash-free binder for the digital inkjet-dyed polyester fabrics. The results showed that, for 2 wt% KH-560 and 40 wt% hard chain segments, the SWPU film had good water resistance, mechanical properties, and adhesion properties, and the best dispersed dye directional effect. With the addition of SWPU in the dye ink of 8 wt%, the front K/S value of the SWPU wash-free digital inkjet-dyes fabric reached 16.86, and the dry/wet rubbing fastness achieved grades 4–5 and 3–4, respectively. Compared with the pure dye inkjet-dyed fabric, its front K/S value increased by 23.9 %, and its dry/wet rubbing fastness improved by grades 1 and 0.5, respectively.