BEHAVIOR OFEUCALYPTUS GLOBULUSLIGNIN DURING KRAFT PULPING. I. ANALYSIS BY CHEMICAL DEGRADATION METHODS
- 12 January 2002
- journal article
- Published by Taylor & Francis in Journal of Wood Chemistry and Technology
- Vol. 22 (2-3) , 93-108
- https://doi.org/10.1081/wct-120013355
Abstract
Eucalyptus globulus wood was subjected to kraft pulping, reaching different extents of delignification. The residual and dissolved lignins were isolated by soft acidolysis and acidic precipitation, respectively, and submitted to analysis of residual sugars and methoxyl groups, as well as to analysis by nitrobenzene and permanganate oxidation and thioacidolysis. Results from both residual and dissolved lignins analyses indicated that in the initial phase of pulping there is a preferential removal of lignin enriched in guaiacylpropane (G) and p-hydroxyphenylpropane (H) units, which is highly condensed and bonded with polysaccharides, predominantly with xylan. During the bulk and residual phases of pulping, lignin enriched in syringylpropane (S) units is progressively removed, leading to the increase of S/G ratio of black liquor lignin. After a purification step of dissolved lignins, two fractions with distinct levels of carbohydrates and with different structural features were obtained. The overall...Keywords
This publication has 15 references indexed in Scilit:
- Chemical Structure of Residual Lignin from Kraft PulpJournal of Wood Chemistry and Technology, 1996
- Structural and Molecular Properties of Residual Birch Kraft LigninsJournal of Wood Chemistry and Technology, 1994
- ThioacidolysisPublished by Springer Nature ,1992
- Chemical Degradation Methods: Permanganate OxidationPublished by Springer Nature ,1992
- The Dissolution and Condensation Reactions of Guaiacyl and Syringyl Units in Residual Lignin during Kraft Delignification of SweetgumHolzforschung, 1990
- The Distribution of Lignin in White Birch Wood as Determined by Bromination with TEM-EDXAHolzforschung, 1988
- Structural Changes in Lignin During Kraft Cooking. Part 5. Analysis of Dissolved Lignin by Oxidative DegradationJournal of Wood Chemistry and Technology, 1987
- Proposed Mechanism for the Nitrobenzene Oxidation of LigninHolzforschung, 1986
- Structural Changes in Lignin During Kraft Cooking Part 3. On the Structure of Dissolved LigninsJournal of Wood Chemistry and Technology, 1984
- Structural Changes in Lignin During Kraft PulpingHolzforschung, 1984