High fixation and low energy consumption in reactive dyeing of cotton through combining the dye molecule design and environment-friendly dyeing technique

To explore methods for achieving clean application of reactive dyes from the source, three polyfunctional reactive dyes (YMR-1–YMR-3) using different diamine compounds as bridge groups were developed. The three dyes showed different solubility in water, which was 230, 100, and 160 g/L, respectively, at 25 ℃. The three reactive dyes were used to dye cotton fabrics through an energy-saving cold pad-batch dyeing technique. The factors influencing on the dyeing performance in the cold pad-batch dyeing technique were also comprehensively studied. The maximum fixation values of YMR-1, YMR-2, and YMR-3 were 94.19, 90.79, and 92.18%, respectively. Levelness of the cotton fabrics dyed with the three dyes was investigated and further discussed. The results showed that the dyed cotton fabrics exhibited good levelness with a low color difference value (Δ E  < 0.40). The dry rubbing fastness of the cotton fabrics dyed with the three dyes was grade 4, and the corresponding wet rubbing fastness was grade 3 or 2–3. The staining fastness of the dyed cotton fabrics was grade 4–5 or 4. The light fastness of the cotton fabric dyed with YMR-1 was grade 4, and that of YMR-2 and YMR-3 was grade 3.