Homogeneous Models for the Chemical Selectivity of Reactive Dyes on Cotton – Development of Procedures and Choice of Model

Rates and products of reactions of a dichlorotriazine dye (C.I. Reactive Orange 4) with a range of alcohols (methanol, propan-1-ol, propan-2-ol, tetrahydropyran-2-methanol, ethane-1,2-diol, alpha- and beta-methylglucopyranosides, mannitol and sorbitol) have been investigated in dilute aqueous solution at pH 11.0 and 25.0 ºC by ion-pair HPLC. The pseudo-first-order rate constants have been separated into contributions from the competing hydrolysis and alcoholysis reactions. Addition of alcohol increases the rates of both hydrolysis and alcoholysis reactions