Synthesis of novel dyes containing a dichlorotriazine group and their applications on nylon 6 and wool

To develop a novel class of reactive disperse dyes devoted to dyeing nylon fabric, cyanuric chloride (1,3,5-tri-chloro-2,4,6-triazine) was used as a reactive component and two new azo reactive disperse dyes were synthesized from intermediate materials. All these dyes were characterized and their structures were confirmed by FT-IR, UV-Visible spectroscopy, elemental analysis, LC-MS spectrometry, and thin-layer chromatography (TLC). Furthermore, the dyes were applied to nylon 6 and wool fabrics at various concentrations, temperatures and pH. The levelness of the dyed samples was measured according to the relative unlevelness index (RUI), and the results illustrated that all dyed fabrics possessed good to excellent color uniformity and build-up. In addition, compared with reactive disperse dyes, corresponding disperse dyes displayed a higher color yield (K/S) due to their chemical structures being more planarity and less bulky. However, their K/S values after reduction clearing were lower than those of reactive disperse dyes, which shows although disperse dyes had higher affinity to nylon 6 and wool, their reaction is limited to the surface of the fabric. Their fastness properties were also examined and compared to those of the corresponding disperse dyes and the result showed that dyes containing a dichloro-triazine group offered better fastness properties than the disperse dyes which can be attributed to the covalent bond formed between the dye molecules and the fiber.