Effect of PEG-400 on dyeing properties of cotton fabric in non-aqueous medium system

Traditional reactive dyeing has the technical problems of high water consumption and high pollution. In this article, the effect of polyethylene glycol 400 (PEG-400) on the dyeing properties of cotton fabrics with high concentration reactive dyes in non-aqueous medium was studied. Initially, the effects of PEG-400 on colour strength (K/S) and colour fastness of dyed fabric with reactive dye are systematically discussed. In addition, the effect of PEG-400 on the hydrolysis properties of reactive dyes was analysed by high-performance liquid chromatography (HPLC). At the same time, the molecular interaction force between the dye and PEG-400 was analysed by ultraviolet-visible (UV-visible) spectroscopy. The results showed that when PEG-400 concentration was 3.0 g/L, K/S value of dyed fabric (5.0%, on weight of fabric, owf) was increased by 33.5%, and is much higher than dyed fabrics without PEG-400. HPLC and UV-visible analysis showed that the addition of PEG-400 effectively reduced the hydrolysis rate of dye II containing two vinyl sulfone reactive groups, which was converted from C.I. Reactive Black 5 containing contains diethylsulfone sulphate group. Its hydrolysis rate was reduced by 20.9%. PEG-400 also decreased the aggregation degree of high concentration reactive dye, and increased the solubility of reactive dye. This method has certain universality. Therefore, using PEG-400 as an additive is an effective way to improve the dye uptake of reactive dyes in non-aqueous medium dyeing system and realise cleaner production.