Bifunctional cationic modification of modal fabric for sustainable in textile dyeing with spent coffee grounds

Abstract

In order to dye cellulose or regenerated cellulose with natural dyes, toxic metal mordants are generally employed. In response to this issue, the novel bifunctional cationic agent was pretreated to modify modal (regenerated cellulose) fabric prior to dyeing to enhance the fiber-dye affinity. The cationization reaction was carried out using a compound containing bicationic sites, N,N'-(oxybis (ethane-2,1-diyl))bis(3-chloro-2-hydroxy-N,N-dimethylpropan-1-aminium. This unique cationic agent is capable of producing nonvolatile amine and has no odor problem. The successful cationic modification was confirmed through FTIR spectroscopy and zeta potential measurement. The cationized process was optimized at a cationic and sodium hydroxide concentration of 90 and 20 g∙L‒1, respectively, with a duration of 5 h. The modified modal fabric significantly enhanced its dyeability with the extract from spent coffee grounds, resulting in deep brown colors. The cationized sample's color strength was noticeably improved. Cationized samples demonstrated better color fastness to washing than untreated samples. Crock fastness was comparable, except the light fastness at high dye concentrations was slightly lower. By utilizing cationization, it offers a promising and sustainable approach enhancing the dyeing with natural dye for green textile coloration.