Synthesis of blocked waterborne polyurethane with 3,5-dimethylpyrazole for industrial application in digital inkjet printing

In this article, a series of blocked waterborne polyurethanes (BWPUs) were synthesized by isophorone diisocyanate, polyols, dimethylol butanoic acid (DMBA), and 3,5-dimethylpyrazole. BWPUs were applied to digital inkjet printing of textiles. The successful synthesis and deblocking of BWPU were confirmed by Fourier transform infrared spectroscopy and differential scanning calorimetry. The colorfastness was improved by deblocking the terminal NCO groups at 140 °C, which could react with fiber. This article presented a characterization method of filtering rate to evaluate the fluency of inkjet printing. Besides, the digital microscope was used to investigate the pigment transferred to the white test cloth. In the end, we chose poly(ethylene glycol adipate) 2000 as the polyol, 1,4-butanediol as the chain extender, 1.6 as the NCO/OH molar ratio, and 4% as the mass fraction of DMBA. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47765.