A novel approach for dyeing of polyester using non-aqueous deep eutectic solvent as a dyeing medium

Purpose Textile industry is considered to be one of the largest consumers of water. There needs to be an alternative for water in textile wet processing. Solvent dyeing can be an approach to replace the use of water in dyeing for water conservation. Design/methodology/approach In this study, the dyeing of polyester was carried out using conventional and solvent dyeing methods. The solvent used was non-aqueous, deep eutectic solvent (DES) prepared using choline chloride and urea. Dyeing parameters such as time, temperature and pH were optimized for a concentration of dye using the solvent and were compared with the conventional dyeing. Findings The prepared solvent was characterized in terms of Fourier-transform infrared resonance and 1 H and 13 C nuclear magnetic resonance to analyze the reaction between choline chloride and urea. Dyeing performance in terms of K/S and fastness properties of dyed fabrics were evaluated and found to be at par against conventional dyeing. Originality/value Use of DES as a dyeing medium is a novel approach in the textile industry.