Abstract:

Hydrolysis reactivities and stabilities of a bis(monofluoro-s-triazine) reactive dye C.I. reactive Red 268 at 130℃ and pH of 7.0-8.0 were studied by reverse-phase ion-pair high performance liquid chromatography(HPLC). The hydrolysis rate coefficients of the bis(monofluoro-s-triazine) form and monofluoromonohydroxybis-s-triazine form of the dye, K1 and K2 were calculated respectively. With the pH value, hydrolysis rate coefficients of thses two forms of the dye kept increasing at  130℃, and the hydrolysis rate coefficients of the dye raised by 8.8 times and 30.2 times respectively when the pH value increases from 7.0 to 7.5 and 8.0. The difference between reactivity of bis(monofluoro-s-triazine) form and monofluoromonohydroxybis-s-triazine form of the dye at high temperature(130℃) decreased significantly, comparing with that at 70℃ and 80℃adn at pH of 11.0. And as by-product of the hydrolysis reaction, the amounts of degradation products of the dye at 130℃ are equivalent to that at 80℃, which implied a good stability for the parent dye at high temperature.

Key words: reactive dye, bis(monofluoro-s-trazine) reactive dye, hydrolysis, kinetics, high temperature