A study of PEG-based reverse micellar dyeing of cotton fabric: reactive dyes with different reactive groups

Reverse micellar dyeing of cotton fabrics with PEG-based non-ionic surfactant in heptane non-aqueous medium with the use of reactive dyes with different reactive groups was investigated. Single jersey knitted fabrics were used in this study. The experimental results reveal that samples dyed by both one-bath and two-bath heptane reverse micellar methods can achieve higher colour yield than the conventional water-based dyeing method. Among different reactive dyes, samples dyed with hetero-bifunctional vinylsulfone based reactive dyes could achieved higher colour yield (K/S) than the homo-bifunctional and monofunctional reactive dyes in non-aqueous dyeing medium. Moreover, the ranges of L*, a* and b* value for hetero-bifunctional vinylsulfone based reactive dyes were narrower than homo-bifunctional and monofunctional reactive dyes. In term of levelness, monofunctional reactive dyes generally resulted a better levelness than homo-bifunctional and hetero-bifunctional reactive dyes. Although one-bath heptane method yields high K/S_sum values, the problem of unlevelness should be considered while the use of two-bath heptane reverse micellar method can strike a balance between levelness and colour yield.