The Kismet of Residual During LMS Delignification of High-Kappa Kraft Pulps
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F.S. Chakar
Summary
A series of laccase-mediator treatments (LMS) with 1-hydroxybenzotriazole (HBT) and N-acetyl-Nphenylhydroxylamine (NHAA) (Fig. 1) as the mediators were performed on a laboratory prepared southern softwood conventional kraft pulp (kappa # 75.4). Subsequent to the LMS treatments, the treated pulps were subjected to various oxidatively reinforced alkaline extraction stages (E*). The kappa results suggested that both LMSHBT and LMSNHAA treatments delignified this high-kappa pulp. The E* stages were beneficial in countering the darkening effect observed after the LMS treatments. Structural changes in residual lignins isolated before and after laccase-mediator (LMSNHAA (E*) and LMSHBT (E*)) treatments were explored. The spectral analysis of phosphitylated residual lignins revealed an increase in carboxylic acid content and a depletion of phenolic hydroxyl groups in non-condensed at C-5 lignin moieties. Aliphatic hydroxyl groups were substantially decreased when NHAA was used. Overall, it appears that LMSHBT and LMsNHAA treatments on high-kappa kraft pulps primarily attack phenolic hydroxyl groups in non-condensed at C-5 lignin structures.
Copyright © 2000 by Walter de Gruyter GmbH & Co. KG
Articles in the same Issue
- Species Index
- Author Index
- Contents
- Subject Index
- Yeast and Bacteria as Biological Control Agents Against Fungal Discolouration of Pinus sylvestris Blocks in Laboratory-Based Tests and the Role of Antifungal Volatiles
- Copper Accumulation in the Digestive Caecae of Limnoria quadripunctata Holthius (Isopoda: Crustacea) Tunnelling CCA-Treated Wood in Laboratory Cultures
- Chromated Copper Arsenate Preservative Treatment of North American Hardwoods. Part 1. CCA Fixation Performance
- Medium Density Fibreboard Manufactured from Blends of White Cypress Pine and Non-Durable Wood Species Shows Increased Resistance to Attack by the Subterranean Termite C. lacteus
- Role of a Labile Terpene Compound in the Assessment of the Age of a Fossil Wood from Siena (Tuscany, Italy)
- Neolignan Skeletons and Benzodioxanes Through Chiral Aryl Alkyl Ether Formation
- Use of β-13 C labelled Coniferyl Alcohol to Detect "End-Wise" Polymerization in the Formation of DHPs
- Bleachability of Alkaline Pulps. Part 1. The Importance of β-Aryl Ether Linkages in Lignin
- Solid State NMR Studies on Cellulose Crystallinity in Fines and Bulk Fibres Separated from Refined Kraft Pulp
- Pulping of Whole Jute Plant (Corchorus capsularies) by Soda-Amine Liquor
- Pattern of Alkali Impregnation of Poplar Wood at Moderate Conditions
- Structure and Reactivity of Lignins and Associated Phenolic Acids in Wheat Straw TMP and CTMP Pulps
- Thermal Reactions of N-Methyl-morpholine-N-oxide (NMMO): A General Method for Separation and Quantification of N-Methyl-morpholine-N-oxide and its Main Degradation Products N-Methylmorpholine and Morpholine by Capillary Electrophoresis (CE)
- The Kismet of Residual During LMS Delignification of High-Kappa Kraft Pulps
- Variations in Transverse Fibre Wall Properties: Relations Between Elastic Properties and Structure
- Application of the GAB Sorption Isotherm Model to Klinki Pine (Araucaria klinkii Lauterb.)
- Strain Changes on the Inner Bark Surface of an Inclined Coniferous Sapling Producing Compression Wood
- Effects of Chemical Modification Reagents on Acoustic Properties of Wood
- J.L. McCarthy In Memoriam
- Acknowledgement
Articles in the same Issue
- Species Index
- Author Index
- Contents
- Subject Index
- Yeast and Bacteria as Biological Control Agents Against Fungal Discolouration of Pinus sylvestris Blocks in Laboratory-Based Tests and the Role of Antifungal Volatiles
- Copper Accumulation in the Digestive Caecae of Limnoria quadripunctata Holthius (Isopoda: Crustacea) Tunnelling CCA-Treated Wood in Laboratory Cultures
- Chromated Copper Arsenate Preservative Treatment of North American Hardwoods. Part 1. CCA Fixation Performance
- Medium Density Fibreboard Manufactured from Blends of White Cypress Pine and Non-Durable Wood Species Shows Increased Resistance to Attack by the Subterranean Termite C. lacteus
- Role of a Labile Terpene Compound in the Assessment of the Age of a Fossil Wood from Siena (Tuscany, Italy)
- Neolignan Skeletons and Benzodioxanes Through Chiral Aryl Alkyl Ether Formation
- Use of β-13 C labelled Coniferyl Alcohol to Detect "End-Wise" Polymerization in the Formation of DHPs
- Bleachability of Alkaline Pulps. Part 1. The Importance of β-Aryl Ether Linkages in Lignin
- Solid State NMR Studies on Cellulose Crystallinity in Fines and Bulk Fibres Separated from Refined Kraft Pulp
- Pulping of Whole Jute Plant (Corchorus capsularies) by Soda-Amine Liquor
- Pattern of Alkali Impregnation of Poplar Wood at Moderate Conditions
- Structure and Reactivity of Lignins and Associated Phenolic Acids in Wheat Straw TMP and CTMP Pulps
- Thermal Reactions of N-Methyl-morpholine-N-oxide (NMMO): A General Method for Separation and Quantification of N-Methyl-morpholine-N-oxide and its Main Degradation Products N-Methylmorpholine and Morpholine by Capillary Electrophoresis (CE)
- The Kismet of Residual During LMS Delignification of High-Kappa Kraft Pulps
- Variations in Transverse Fibre Wall Properties: Relations Between Elastic Properties and Structure
- Application of the GAB Sorption Isotherm Model to Klinki Pine (Araucaria klinkii Lauterb.)
- Strain Changes on the Inner Bark Surface of an Inclined Coniferous Sapling Producing Compression Wood
- Effects of Chemical Modification Reagents on Acoustic Properties of Wood
- J.L. McCarthy In Memoriam
- Acknowledgement
