Effect of Temperature on the Kinetics of Hydrolysis of Dichlorotriazinyl Reactive Dyes

The kinetics of the hydrolysis of dichlorotriazinyl reactive dyes have been studied over a range of temperatures and pH values. The results have been examined in accordance with the generally accepted reaction scheme, and methods of calculating the separate rate constants are described. The activation energy of hydrolysis varies with temperature and this variation is thought to be due to changes in the activity coefficient or probability factor with temperature. The equilibrium between two forms of the dye does not have the characteristics of a simple acid-base equilibrium with respect to temperature, indicating that it may not arise from the ionisation of the imino bridging group, as has been generally supposed.