Salt-free reactive dyeing of cotton fibers in a ternary solvent system with different reactive dye chemistry

Abstract

Reactive dye chemistry plays a crucial role in the dyeing of cotton fibers. Herein, to provide insight on the adaptability of salt-free reactive dyeing for sustainable environmental development, the effect of dye chemistry on the dyeing properties of cotton fibers in the proposed EtOH–CCl4–H2O ternary solvent system was investigated in detail. Twelve commonly used reactive dyes were selected as representative dyes and applied to cotton yarns based on their reactive groups, molecular weights, chromophores, and sulfonate groups. Compared with the conventional aqueous dyeing method, almost all reactive dyes showed an enhanced dyeing performance in the EtOH–CCl4–H2O (55:40:5) mixture. Dyeing results of cotton yarns indicated that the investigated copper phthalocyanine dyes and azo dyes are suitable dye categories for dyeing in the EtOH–CCl4–H2O mixture. This study may offer a theoretical strategy for the industrial-scale production of cotton fibers using the developed solvent assisted dyeing technology. The organic solvents recovery will be carried out in the future study.