Kinetics of Hydrolysis of Halogeno-s-triazine Reactive Dyes as a Function of Temperature

The kinetics of alkaline hydrolysis of azo reactive dyes: monofunctional with one monohalogeno-s-triazine reactive group and bifunctional with two identical monohalogeno-s-triazine reactive groups was studied in the temperature range from 50 °C to 80 °C by means of high performance liquid chromatography. From the determined pseudo-first order hydrolysis rate coefficients, the chemical reactivity of particular dyes and their sensitivity to temperature changes according to the Arrhenius equation were evaluated. The hydrolysis rate coefficient of monofunctional dyes is more temperature dependent than that of homobifunctional dyes. Reactive dyes with a less reactive monochloro-s-triazine group are more sensitive to temperature variations than reactive dyes with a more reactive monofluoro-s-triazine group. Among the studied dyes, the bis(monofluorotriazine) form of the homobifunctional dye exhibits the lowest sensitivity to temperature variations.