THE DETERMINATION OF THE DEGREE OF SUBSTITUTION OF CARBOXYMETHYLCELLULOSE OVER THE ENTIRE SUBSTITUTION RANGE

Abstract

The published methods for the determination of the degree of substitution of carboxymethylcellulose were found to be unsatisfactory for samples of high degree of substitution. Two methods were developed: one comprises the removal of the impurities from crude sodium carboxymethylcellulose by dialysis or washing with ethanol and determination of the sodium content; the other is based on the precipitation of cupric carboxymethylcellulose under controlled conditions, purification, and determination of the copper content.