Studies on the Emulsion Xanthation of Cellulose

Abstract

The influences of various treatments (acid-hydrolysis, hypochlorite bleaching, alkali-ageing and cold alkali refining) upon the reactivity of wood cellulose in emulsion xanthation were investigated.
The results were as follows :
1. The solubility of acid-hydrolyzed cellulose in emulsion xanthation was found to be the function of relative viscosity, and it was considerably affected by the conditions of hot alkali treatments (e. g. sulfate cooking and hot caustic purification) of wood cellulose.
2. The solubilities of cellulose, which has been degraded to the same relative viscosity under various methods (acid-hydrolysis, hypochlorite bleaching and alkali-ageing) in emulsion xanthation were investigated.
From this data, it seems that the content of the crystalline region has an effect upon the amount of undissolved residue after emulsion xanthation.
3. It could be supposed that the fine structure of a cold alkali refined cellulose has a greater influence than α-cellulose content (90 g/l NaOH solubility) upon the reactivity of cellulose during emulsion xanthation.
From these investigations, it seems that the solubility of cellulose in emulsion xanthation is dependent upon the fine structure under the conditions used in this experiments.
As the behavior of cellulose during emulsion xanthation seems to agree with that of H₃PO₄ solubility, we think that the emulsion xanthation method appeared to be an useful relative yardstick for measuring the fine structure of cellulose.