Hydrolysis And Dyeing Performance Of Mixed Bifunctional Reactive Dyes

The development of fiber variety and dyeing technology requires higher demands to the character of reactive dye, especially the ecological character. Because the poor efficiency of the traditional reactive dye has caused serious environmental pollution, enhancing the degree of fixation has become the focus. Recently, the formulation and synergistic technology has attracted more and more attention. Among the new methods, the reasonable combination of the mixed bifunctional reactive dyes has become an effective one to improve the application performance of reactive dyes.Due to its similar property and perfect compatibility, "composite reactive dye" composed ofβ-sulfooxyethylsulfonyl group and vinylsulphone with the same matrix can attain synergistic effects and have good application properties. Therefore, the study of hydrolysis and dyeing performance of this kind of "composite reactive dye" is very important.Firstly, the hydrolysis performance of three mixed bifunctional reactive dyes-C.I. Reactive Red 241, C.I. Reactive Yellow 176, C.I. Reactive Blue 2G (R1, Y1 and B1) was investigated by HPLC and HPLC-MS technology under different temperature (40℃,50℃, 60℃) and pH value (7.09,7.99,10.1). Then the hydrolysis condition for preparing the "composite reactive dye" which includesβ-sulfooxyethylsulfonyl group and vinylsulphone group was provided.In order to compare the effect of arrangement of two reactive groups on dyeing performance, three reactive dyes (R2, Y2 and B2) which are the isomers of R1, Y1 and B1 were desighed and synthesized respectively. Their spectral properties were analyzed. The structures of the synthesized dyes were confirmed by visable spectrum and API-MS. The respective "composite reactive dye" of R1, R2, Y1, Y2, B1 and B2, which contained different ratio ofβ-sulfooxyethylsulfonyl group and vinylsulphone group, were obtained by hydrolyzing under 40℃and pH 7～10.The "composite reactive dye" of R1, R2, Y1, Y2, B1 and B2 were dyed on cotton fabrics under its their optimum dyeing condition resprctively. The dyeing properties were comprehensively studied by the following dyeing performance parameters-S, R, E, F.Within the scope provided by this article, the results showed that, regardless of unilateral or bilateral mixed bifunctional reactive dye complex, their substantivity (S) both went up as the content of vinylsulphone group increased and levelled off finally. However, the reactivity (R), exhaustion (E) and fixation (F) maintained stability generally. It was showed thatβ-sulfooxyethylsulfonyl reactive dye and vinylsulphone reactive dye with the same base manifested silmilar (R, E, F). Moreover, the dyeing performance of the unilateral composite reactive dye was much better than the bilateral one.