The Difference of Reactivity between Hydroxyl Groups of Cellulose in the Preparation of Carboxymethyl Cellulose

Abstract

As the effect of carboxymethyl cellulose (CMC) is related to the distribution of carboxymethyl groups among each OH group in anhydrous glucose unit in many cases, in order to investigate the reactivity of the primary and the secondary OH groups of cellulose in the case of the preparation of CMC by organic solvent method, the quantity of dialdehyde group of the NaIO₄ oxidized CMC of various degree of etherification (DS) was determined.
It is considered that in this condition of the reaction at least, the primary OH groups in cellulose are mainly subjected to carboxymethylation up to DS of about 1.0, but from the vicinity of 0.9 of DS the secondary OH groups in it become also to receive the reaction and above 1.1 the latter groups undergo exclusively.