Hydrolysis Of Vinyl Sulfone Reactive Dyes And Their Dyeing Properties For Viscose Fibers

In this study, the viscose fiber was dyed by three kinds of active dyes including Reactive Turquoise Blue CGF, Reactive Brilliant Blue CPF and Reactive Red 3BSN, respectively. The dyes structure was studied and the effect of dye concentration, sodium chloride and sodium carbonate concentration on the dye uptake, fixation rate and K/S value was investigated. In addition, the hydrolysis reaction of the three dyes were investigated using pH variation analysis and high performance liquid chromatography method, respectively, and the difference in the reaction rate between the dyes was also studied. The results indicate that the reactive group of the three kinds of dyes was vinyl sulfone sulfate group, and the matrix of Reactive Turquoise Blue CGF, Reactive Brilliant Blue CPF and Reactive Red 3BSN are the phthalocyanine, anthraquinone and naphthalene structure, respectively. Dye concentration exhibited little influence on the dyeing effect of Reactive Turquoise Blue CGF and Reactive Red 3BSN, while the Reactive Brilliant Blue CPF obtained its highest dye uptake, fixation rate and K/S value at owf 4%. In addition, sodium chloride greatly accelerated the dyeing process of three dyes, while the optimum sodium carbonate concentration of them was found to be 20g/L,20g/L and 18g/L. Furthermore, Reactive Turquoise Blue CGF and Reactive Brilliant Blue CPF exhibited higher hydrolysis reaction rate especially under higher temperature conditions, while the hydrolysis reaction rate of Reactive Red 3BSN is rather slow. Under alkaline conditions, the elimination reaction of sulfate group would occur to form the vinyl sulfone dyes, which could react with water immediately to produce the hydrolysed dyes. Because of the difference in dye matrix structure, the two dyes exhibited different S, E, F and R values, which give them different dyeing property on viscose fiber.