Application of GPC to Studies of the Viscose Process. II. The Effects of Steeping and Alkali-Crumb Aging
作者:
John Dyer,
L.H. Phifer,
期刊:
Separation Science
(Taylor Available online 1971)
卷期:
Volume 6,
issue 1
页码: 89-99
ISSN:0037-2366
年代: 1971
DOI:10.1080/00372367108055553
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
Changes in the distribution of degree of polymerization (DP) of cellulose during the steeping and alkali-crumb aging steps of the viscose process have been studied. A dissolving-grade pulp was used, and two mechanisms of degradation—oxidation and hydrolysis—were considered. Alkaline hydrolysis was relatively unimportant during the steeping, the major change in the DP distribution being a result of the much faster oxida-tive degradation. The extent of oxidation was determined by the solubility of oxygen in the alkali solution. Both oxidation and hydrolysis cause degradation during the aging of alkali crumb. Under the conditions used, hydrolysis was a slow, pseudo-first-order reaction, and oxidation a much faster zero-order reaction. Since there was a large difference in the rates of these reactions, the kinetics of degradation approached zero order.
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