Structural Analysis of Residual and Technical Lignins by 1H-13C Correlation 2D NMR-Spectroscopy
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Ewellyn A. Capanema
Summary
Structural analysis was conducted on residual lignin from pine Kraft AQ pulp, Eucalyptus Kraft lignin from Eucalyptus globulus and Repap Organosolv lignin by 2D 13C-1H correlation NMR spectroscopic techniques such as HMQC sequence. These lignins contain a rather wide variety of saturated aliphatic groups. The HMQC NMR spectra of the lignins do not verify the presence of diarylmethane moieties in any lignin investigated. The type and amount of other condensed structures depend on the nature of lignin preparation. All the lignins investigated still contained β-O-4′, pino- and syringayresinol (β-β′) and phenylcoumarane (β-5′) structures. Stilbene structures were also identified. Vinyl ether structures were present only in Eucalyptus Kraft lignin. All the lignins contain α-carbonyl groups conjugated to aromatic moieties as terminal side chains rather than involving β-O-4′ structures. No coniferyl alcohol and coniferyl aldehyde type structures are detected in the lignins after pulping. The spectra of kraft lignins show some new signals, the origin of which is discussed.
Copyright © 2001 by Walter de Gruyter GmbH & Co. KG
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- Lipophilic Extractives from Eucalyptus globulus Pulp during Kraft Cooking Followed by TCF and ECF Bleaching
- Determination of Monosaccharide Composition of Eucalyptus globulus Wood by FTIR Spectroscopy
- Acetyl Group Distribution in Acetylated Wood Investigated by Microautoradiography
- Solid State NMR Analysis of β-13C-Enriched Lignocellulosic Material During Light-Induced Yellowing
- N-Hydroxy Compounds as New Internal Standards for the 31P-NMR Determination of Lignin Hydroxy Functional Groups
- 19F NMR Spectroscopy for the Quantitative Analysis of Carbonyl Groups in Lignins
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- Experimental Determination of Stiffness Variation Across Growth Rings in Picea abies
- Determination of the Material Property Variations Across the Growth Ring of Softwood for Use in a Heterogeneous Drying Model Part 1. Capillary Pressure,Tracheid Model and Absolute Permeability
- Surface Area Determinations in Woodpulps by Humidity Adsorption
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- Literature Reports
Articles in the same Issue
- Characterisation of Fungal Degraded Birch Wood by FTIR and Py-GC
- The Effects of Specific Volatile Organic Compounds Produced by Trichoderma Spp. on the Growth of Wood Decay Basidiomycetes
- Biological Control of Blue Stain in Pulpwood: Mechanisms of Control used by Phlebiopsis gigantea
- Cell-Wall-Associated Peroxidases from the Lignifying Xylem of Angiosperms and Gymnosperms: Monolignol Oxidation
- Laboratory Evaluation of Natural Decay Resistance and Efficacy of CCA-Treated Rubberwood (Hevea brasiliensis Muell. Arg.)
- Inhibition of the Photodiscoloration of Wood by Butyrylation
- Lipophilic Extractives from Eucalyptus globulus Pulp during Kraft Cooking Followed by TCF and ECF Bleaching
- Determination of Monosaccharide Composition of Eucalyptus globulus Wood by FTIR Spectroscopy
- Acetyl Group Distribution in Acetylated Wood Investigated by Microautoradiography
- Solid State NMR Analysis of β-13C-Enriched Lignocellulosic Material During Light-Induced Yellowing
- N-Hydroxy Compounds as New Internal Standards for the 31P-NMR Determination of Lignin Hydroxy Functional Groups
- 19F NMR Spectroscopy for the Quantitative Analysis of Carbonyl Groups in Lignins
- Reactions of the β-Aryl Ether Lignin Model 1-(4-Hydroxy-3-Methoxyphenyl)-2-(2-Methoxyphenoxy)-1-Propanol on Heating in Aqueous Solution
- Structural Analysis of Residual and Technical Lignins by 1H-13C Correlation 2D NMR-Spectroscopy
- Experimental Determination of Stiffness Variation Across Growth Rings in Picea abies
- Determination of the Material Property Variations Across the Growth Ring of Softwood for Use in a Heterogeneous Drying Model Part 1. Capillary Pressure,Tracheid Model and Absolute Permeability
- Surface Area Determinations in Woodpulps by Humidity Adsorption
- A Simple Testing Method for the Measurement of the Water Vapour Transmission of Coated Wood Longitudinal and Tangential to Grain Direction
- Literature Reports
