Pretreatment optimization process of cotton to overcome the limits of its dyeability with indigo carmine

Abstract

Cationization of cotton is emerging as an effective approach that solves problems associated with dyeing cellulosic fibers, especially cotton, by using indigo carmine. Indeed, this dye has no affinity for cellulosic fibers. Also, it has low fastness to light and washing. In this research, cotton modification is carried out by using Sera Fast GMX cationic agent in order to improve the yield of the exhaustion dyeing process by indigo carmine. The physical and chemical properties of unmodified cellulose fibers, as well as cationic modified cellulose fibers, were compared and investigated by SEM, FTIR and thermogravimetric analysis (TGA). The effect of the cationization process conditions, namely cationizing agent concentration, temperature of cationization, time of cationization and alkali concentration on the performances of dyeing of cotton by indigo carmine were studied, then the results were assessed by measuring the color strength (K/S) and the dyeing bath exhaustion E(%). Finally, a Box-Behnken experimental plan was used for experimental design and optimization of the dyeing parameters. The dyeing results of the optimized process conditions illustrate that cationization improves the fabric dyeability compared to the untreated cotton and the different fastness properties.