The Methylation of Cellulose Xanthate1

Abstract

The distribution of xanthate groups along cellulose chains in commercial viscose solutions very probably affects the processing qualities of the viscose and also the physical properties of the spun yarn. The rayon manufacturer, therefore, as well as the cellulose chemist, is interested in knowing what that distribution is. Xanthate groups are too unstable to permit direct determination of their location; attempts have been made to fix their location by quantitative replacement with methoxyl groups. After hydrolysis of the methylcellulose thus produced to methylglucoses, various means have been used to identify the latter, but the results have not been sufficiently accurate to determine the positions of the original xanthate groups. In the present work use was made of chro matographic methods to separate and identify the products of hydrolysis. However, during a careful re-examination of the methylation procedure it has been found that about 20% of the xanthate groups are not replaced but are converted to the S-methyl ester. In this form they are lost during hydrolysis. Hence, although adequate means are now available for determining the positions of methyl groups in methylcellulose, better means of replacing xanthate groups must now be sought if the original problem is to be solved.