Preparation Of Water-soluble Pu-based Polymeric Dye And Dyeing Of Cellulosic Fiber

In this work, a new type of water-soluble polyurethane-based polymeric reactive dye was synthesized by diazo coupling reaction, which means that the diazo sulfatoethylsulfone chromophore was grafted onto the main chain of polyurethane. Molecular weight and polydispersity of polymeric dye were tested by GPC analysis,and the result was Mn=31700, Mw=46000, polydispersity= 1.45. The structure of the polymeric dye was characterized by using IR, Raman, 1HNMR, UV–visible analysis, and the results proved that the structure of the polymeric dye was the same as designed.The thermal properties and thermal decom- position properties were analyzed by TG-IR, and the result showed that the polymeric dye had good thermal stability during dyeing. The solubility of the polymeric dye was also analysized, and the result showed that the polymeric dye had good solvent resistance in room temperature. We also found that the polymeric dye can be completely dissolved in water above 80℃. The pH response performance of the polymeric dye was analysized, and the results showed that the polymeric dye had great pH response performance, especially with the acidity increased, the dye solution showed obvious bathochromic-shift phenomenon.The optical response performance of the polymeric dye was also analysized, and the results showed that the polymeric dye had optical response performance under 365nm UV light exposure, but the optical response speed was slow. The dyeing properties of the polymeric dye on cotton fabric were discussed, dyeing technics used a one-bath exhaust dyeing, the effect factors of dyeing properties on cotton were discussed, such as different alkaline, pH value, bath ratio, alkaline concentration, electrolyte concentration, dyeing temperature, fixing temperature and so on. The results showed the polymeric reactive dye had high fixation and good fasteness to washing and rubbing on cotton fabric, both can reach 4~5 grade. Also we found a suitable dyeing technics on cotton fabric: bath ratio 30:1, NaHCO3 concentration 15g/L, Nacl concentration 25g/L, dyeing temperature 60℃, fixing temperature 60℃.The dyeing properties of the polymeric dye on ramie fabric were discussed, dyeing technics used a one-bath exhaust dyeing, the effect factors of dyeing properties on ramie fabric were discussed, such as different alkaline, pH value, bath ratio, alkaline concentration, electrolyte concentration, dyeing temperature, fixing temperature and so on. The results showed the polymeric reactive dye had high fixation and good fasteness to washing and rubbing on ramie fabric, both can reach 4 grade. Also we found a suitable dyeing technics on ramie fabric: bath ratio 30:1, NaHCO3 concentration 20g/L, Nacl concentration 20g/L, dyeing temperature 80℃, fixing temperature 80℃.