Cationic cotton modified by 3-chloro-2-hydroxypropyl trimethyl ammonium chloride for salt-free dyeing with high levelling performance

Traditional dyeing process of cotton has caused a large amount of wastewater with high salt content, which seriously damages the ecological environment. In this work, cotton fabric was modified with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride in order to decrease the electrostatic repulsion with the anionic dyes. A systematic optimization of the process has been performed. The acid dyes were applied instead of the common reactive dyes to dye the modified fabrics. The advantage of the high dye-uptake of acid dyes is studied. The levelness of the fabric dyed by reactive dyes and acid dyes were compared. The adsorption process and the bindings between the modified fabric and anionic acid dyes were further explored. The dyeing process were optimized. Finally, the dye-uptake of the modified fabric dyed by optimized conditions achieves to about 92%, which is comparable to traditional cotton dyeing process.

Automated summary

This study improved the traditional cotton dyeing process, reducing the harm to the ecological environment caused by high-salt wastewater discharge, and achieved a high dye-uptake rate.