Modification of Viscose Rayon Fabric with 3-Chloro-2-Hydroxypropyl Trimethyl Ammonium Chloride (CHPTAC) to Enable its Sustainable Dyeing with Acid Dyes

This study explores the application of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride as a cationizing agent to modify viscose rayon fabric by the pad-batch method. This modification overcomes the electrostatic repulsion between negatively charged cellulose and acid dyes during dyeing, enabling dyeing without the need for electrolytes. Thus the dyeing of the cationized viscose rayon fabric is achieved with the negatively charged acid dyes without any electrolyte. The dyeing properties of unmodified and modified fabric samples with three different acid dyes (Lanasyn Orange NLI, Brillion Brill Red MF/3B 140, and Nyloson Navy NRBL 220) with the shade depths as 1%, 2%, 4%, and 6% owf by exhaust method are examined. The results indicate that modified viscose rayon fabric offers significant color yield values and improved fastness properties such as washing, light, perspiration, and rubbing. The novelty of this research lies in the ability to dye cellulosic fibers such as viscose in this case with acid dyes, while originally these dyes are typically used to color polyamide fibers.