A short-time, low-dosage chemicals dyeing of polyester/cotton blended fabric with benzothiazole dyes in water-less, salt-free dyeing system

Int J Biol Macromol. 2024 Nov 27;284(Pt 1):138159. doi: 10.1016/j.ijbiomac.2024.138159. Online ahead of print.

Abstract

Non-aqueous media dyeing technology has highly innovative as it reduces pollution without increasing cost in polyester/cotton blended fabric dyeing. However, disperse dyes can stain in cotton component of the polyester/cotton blended fabric during dyeing process, resulting poor quality of dyed products. In this study, a groundbreaking comprehensive investigation was conducted on the dyeing behavior of C.I. Disperse Red 177 and C.I. Disperse Red 145 in non-aqueous media. The results revealed that the dyes' uptake rates on polyester components in non-aqueous medium were comparable to those in traditional water dyeing baths. Conversely, the staining rate of disperse dye on cotton fiber surface was relatively high. Interestingly, the migration of dyes from polyester surface to cotton surface after dyeing had minimal impact on staining. Thermodynamic analysis in non-aqueous media showed that the Gibbs free energy of C.I. Disperse Red 145 adsorption on cotton was higher than that of C.I. Disperse Red 177. Computational chemistry simulations showed that the terminal group of C.I. Disperse Red 177 (N-acetoxyethyl) led to stronger electrostatic interaction with cotton compared to C.I. Disperse Red 145. Therefore, disperse dyes with N-ethyl end groups have a weak interaction with the cotton and stain less on the cotton fiber surface.

Keywords: Non-aqueous medium; Polyester/cotton blended fabrics; Staining.