KINETICS OF DIMERIZATION OF VINYLSULFONYL REACTIVE DYES

ABSTRACT: The hydrolytic reactions of three vinylsulfonyl (VS) reactive dyes, C. I. Reactive Yellow 17, Orange 16 and Blue 19, were kinetically investigated. The second-order rate constants of the hydrolysis for the sulfatoethylsulfonyl and VS types as well as of the forward and backward reactions of dimerization between the VS and β-hydroxyethylsulfonyl types were estimated. The kinetic parameters were determined so that the theoretical concentrations calculated numerically from the simultaneous reaction equations coincided with the corresponding experimental ones each other. The rate constants of dimerization varied considerably with dyes: Blue 19 > Yellow 17 > Orange 16. Those of decomposition for the dimer were in the following order: Yellow 17 > Blue 19 > Orange 16. Blue 19 has a high stability of dimer and Yellow 17 a low one. Orange 16 forms it only at higher concentrations. The ratios of the second-order rate constant of the hydrolysis to that of the reaction with cellulose were confirmed to be nearly constant for VS dyes examined.