An innovative method for improving dyeing yield of the cellulosic substrate using additives in NaOH-water eutectic mixture.

Farazandemehr, Elham; Khoddami, Akbar; Dinari, Mohammad

A novel method has been investigated to remove the conventional mercerizing drawbacks in an attempt to reduce sodium hydroxide consumption along with introducing an environmentally friendly feasible method to improve the dyeing and related properties. It was found that a binary and tertiary mixture of urea, thiourea, and sodium hydroxide could potentially fulfill this purpose. Experiments were carried out under different treatment time, temperature, and concentration of each component in the mixture. Dye properties of treated dyed samples after chemical modification in the form of K/S values were calculated. The changes in the samples' characteristics were evaluated by ATR-FTIR spectroscopy, microscopic examination, mechanical and pilling properties. The results indicated that a proper concentration of all three chemicals could enhance the dyeing properties of the substrate by which the NaOH concentration decreased from 300 to 160 g/lit. The novel eutectic solvent did not show an adverse effect on the sample's tensile and other properties.