Studies on some radical transfer reactions by entrapping the radicals as polymer endgroups. Part IV. Reaction of the ȮH radical with carboxylic acids

Abstract

AbstractThe reaction of the OH radical with some carboxylic and hydroxycarboxylic acids was investigated by trapping the resultant radicals as endgroups of poly(methyl methacrylate), which were detected and estimated by the sensitive dye partition technique. The rate constants of the reaction at 25°C and pH = 1.0 with formic, propionic, butyric, valeric, lactic, and tartaric acids were determined. The increasing reactivity of the acids with increasing chain length is explained by the decreasing deactivation of the CH2 group, from which H‐abstraction occurs, by the preceding COOH group. The higher reactivity of formic acid than acetic or propionic acid, and the higher reactivity of lactic acid than propionic acid are explained by the increased electron density at the site of H‐abstraction.