Oxygen Degradation and Spectroscopic Characterization of Hardwood Kraft Lignin
| Autor: | Hasan Jameel, Arthur J. Ragauskas, Lucian A. Lucia, Rallming Yang |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
General Chemical Engineering
Pulp (paper) technology industry and agriculture food and beverages chemistry.chemical_element General Chemistry engineering.material complex mixtures Oxygen Industrial and Manufacturing Engineering Absorbance chemistry.chemical_compound stomatognathic system Kraft process chemistry engineering Hardwood Lignin Organic chemistry Chemical decomposition Kraft paper Nuclear chemistry |
| Zdroj: | Industrial & Engineering Chemistry Research. 41:5941-5948 |
| ISSN: | 1520-5045 0888-5885 |
| DOI: | 10.1021/ie020007k |
| Popis: | A series of sweet gum kraft pulps with initial kappa numbers ranging from 29 to 13.6 was subjected to oxygen delignification employing 1.00 and 4.00% charges of caustic. The O-delignified pulps were characterized according to lignin content, pulp yield, and viscosity. In addition, residual lignin samples were isolated from the kraft brownstock and the post-oxygen-delignified kraft pulps, along with the corresponding O-effluents. The structural changes of these lignins during oxygen delignification were investigated using UV spectroscopy and advanced NMR techniques. Differential UV spectra indicated that lignins isolated from oxygen-delignified kraft pulp and its effluent were significantly reduced at λmax 260, 280, and 370 nm in comparison to the brownstock lignins. These changes in absorbance are attributed to the degradation of phenolic and stilbene structures during oxygen delignification. 31P NMR lignin data revealed that the primary sites of oxidation during an O-stage were syringyl and guaiacyl phen... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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