RESEARCHES ON VISCOSE SILK (IV.)

ON THE ANALYSIS OF VISCOSE

Abstract

One of our collaborators had shown a method of the analysis of alkalies in viscose, in which the alkalies in crude viscose were assumed to exist in four states as viscose-, caustic-, carbonate- and sulphide-alkali, and studied on their chemical changes during aging of viscose. Recently, however, besides these alkalies, the presence of sodium trithiocarbonate has been generally recognized in viscose and also estimated by Bernhardt, Wyss, etc.
The authors have studied on this compound and found that this can be experimentally estimated by volumetric way with iodine, and have also modified the above method of analysis in the presence of this compound.
The results obtained are as follows :
(1) Trithiocarbonate is quantitatively estimated by means of iodine and this chemical reaction is monomolecular one. From the experimetal fact the chemical reaction between them may be expressed by the following equation :
Na₂CS₃+I₂=2NaI+CS₂+S
(2) According to a new modified method of analysis, alkalies in crude viscose, namely viscose-, caustic-, carbonate, sulphide and thiocarbonate-alkali are able to be determined. This method is also recommendable to study their chemical changes during aging of viscose with considerable exactness of result and easiness of manipulation.