Increasing the stability of cellulose dissolved in cuprammonium hydroxide

Abstract

The cupri-ethylenediamine and the modified cuoxam methods used in measuring the degree of polymerization of cellulose are reviewed. A comparative study of the degradation of cellulose in these solvents has been undertaken. The accuracies of measurements by using these methods and a new modified cuoxam method are undertaken. The addition of sodium sulphite and sodium bisulphite to the cuoxam solution in amounts of 0·6-1·4 g/50 ml protects cellulose against oxidation during the dissolving process. This modified cuoxam method can be compared in its accuracy to the cupri-ethylenediamine method where the change in the viscosity of cellulosic solutions during the measuring process is negligible. © 1965.