Esterification of the carboxyl groups in wool

Abstract

The effect of concn. of acid catalyst, temp. and water on the esterification of the carboxyl groups in wool with alcohols was studied. The number of carboxyl groups capable of being esterified decreases with increasing molecular wt. of the alcohol. The esters formed are readily saponified by alkali and the rate of this reaction is independent of the alcohol used. Of a number of 1,2-epoxides examined, only epichlorhydrin esterified more than 10% of the carboxyl groups of wool. The ester of monochlorhydrin formed reacts with dilute alkali at room temp. to form an epoxide which is combined in the wool. The effects of esterifying the carboxyl groups on the titration curve, dyeing behavior and elastic properties of wool were investigated. The combination of acids with wool can be greatly speeded up by efficient agitation and equilibrium established in a few minutes.