Synthesis And Application Of Polyurethane Rubbing Fastness Improver For Dyed Wool

In recent years, with the improvement of people’s living standard and wool products changing, the production and consumption of wool fabric are getting more and more. Acidic dyes and acid mordant dyeing dyes are usually used for wool, and acid mordant dyeing dye is widely used in China because of its low price and many kinds of good fastness. However, the rubbing fastness of wool fabric with brunet acid mordant dyeing dye is not ideal. In the process of wear, especially wearing with light colored clothes mixed, it tend to produce a phenomenon of color pollution, and meanwhile, because countries around the world had higher requirement on rubbing fastness properties of the imports of textiles, which had tremendous negative impacts on the textile exports of China.In order to solve this problem, two kinds of modified waterborne polyurethane were synthesized in this paper. one kind is modified with polyamine, and the other one is with s-triazine, which were used to improve rubbing fastness of dyed wool with acid mordant dyes as improver.The polyurethane prepolymer with -NCO terminal groups was synthesized from toluene diisocyanate （TDI） and polyethylene glycol （PEG）, and it was on this basis that two kinds polyurethane were synthesized. In the reaction process of multiple amine and prepolymer, influencing factors, e.g. molar ratio of NH₂/NCO, reaction temperature and time and feeding methods, were investigated in detail. Finally a polyurethane terminated with amine was developed. After treated with the polyurethane modified with polyamine dry rubbing fastness of dyed wool was improved from 3 to 3～4, and wet fastness was not improved,while after treated with the polyurethane modified with s-triazine, the dry fastness was improved from 3 to 4 and wet fastness was improved from 3 to 4～5,and which performed well in the tests of washing durability.The application of this rubbing fastness improver was also discussed in this paper. Factors such as curing temperature, pH value and amount of improver were discussed and a proper process was gained. It is proven by results that color fastness of wool fabrics dyed with acid mordant dyeing dyes could be improved noticeably by the improver developed in this paper while few negative influences were observed.