Sustainable dyeing of nylon with disperse dyes in Decamethylcyclopentasiloxane waterless dyeing system

Because of the prevailing issue of water scarcity, the application of non-aqueous media Decamethylcyclopentasiloxane (D5) was employed in the chemical fiber dyeing and washing process. Confocal laser scanning microscope (CLSM) and X-ray photoelectron spectroscopy (XPS) analysis have been carried out to analyze the penetration of D5 into the interior of nylon fiber and its distribution in fiber cross-section. The solubility of pure disperse dye in D5 has been measured to check the feasibility of dispersing agent exclusion from dyeing formulation. For developing the solvent dyeing and washing process for nylon, nylon fabric was dyed with pure disperse dyes in D5 solvent and washed with D5 without any process auxiliaries. Findings from CLSM and XPS spectrum showed that D5 can diffuse into the nylon fabric surface with and without the addition of accelerant. And accelerant doesn't affect D5's ability to penetrate and uniform distribution within the fiber structure. As compared to aqueous dyeing, the 30 and 43 percent increase in K/S was achieved for azo and anthraquinone dyes by using D5 as dyeing media. Furthermore, more than 99 percent solvent can be recycled or recovered. The level dyeing with commercial dyes under conventional dyeing conditions in D5 solvent dyeing media prove the commercial feasibility of this dyeing technology. (C) 2020 Elsevier Ltd. All rights reserved.