Condensation reactions of lignin during oxygen delignification under acidic conditions
authors Evtuguin, DV; Neto, CP; Silvestre, AJD
journal JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY
keywords ACETONE; MEDIA; WOOD
abstract Spruce wood (Picea abies) has been subjected to delignification by oxygen under acidic conditions using different solvent media. The residual and removed lignins were submitted to permanganate oxidation and the products analyzed by GC and GC-MS. Results from the analysis of the residual lignins indicate that lignin ''condensation'' depends on the nature of oxidation medium. It was found that the addition of acetone to the aqueous liquor decreases both acid catalyzed and radical side reactions. Lignin ''condensation'' in water containing media is dominated by radical reactions. Results from the analysis of the lignin removed during oxygen delignification in an acetone/water medium indicate that significant amounts of ''condensed'' structures are present, which are relatively stable towards oxidation. The presence of diphenylmethane, diarylether and biphenyl type structures in the removed lignin was confirmed by CP-MAS C-13 NMR spectroscopy.
publisher TAYLOR & FRANCIS INC
issn 0277-3813
year published 1997
volume 17
issue 01-fev
beginning page 41
ending page 55
digital object identifier (doi) 10.1080/02773819708003117
web of science category Materials Science, Paper & Wood
subject category Materials Science
unique article identifier WOS:A1997XC69800003
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journal analysis (jcr 2017):
journal impact factor 1.418
5 year journal impact factor 1.539
category normalized journal impact factor percentile 83.333
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