Impact of Reactive Dye Structures on Dyeing Properties in Salt-free Reactive Dyeing

摘要

The cationic cotton was obtained by pretreatment with tertiary amine cationic polyacrylamide, and dyed with various active groups reactive dyes in the absence of salt. The influences of reactive dye structures on dyeing properties were analyzed and the results showed that types of active groups in reactive dyes had little effect on dye exhaustion, but it was quite relative with dye reactivity and fixation. Reactive dyes with low molecular weight and more anionic groups were adsorbed more quickly on the cationic cotton and their adsorption time to reach adsorption equilibrium was shorter, compared with that with large molecular weight and less anionic groups. Moreover, exhaustion of reactive dyes with large molecular structures decreased due to sterically hindered effect in the salt-free dyeing. The results also displayed that the monochlorotriazine reactive dyes and the vinyl-sulfone ones were favorable to dye the cationic cotton without salt addition.