Journal ArticleDOI
2 Chloro 4,4,5,5 tetramethyl 1,3,2 dioxaphospholane, a reagent for the accurate determination of the uncondensed and condensed phenolic moieties in lignins
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TLDR
The use of 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane as a reagent in quantitative 31P NMR analysis of the hydroxyl groups in lignins has been thoroughly examined, and an experimental protocol recommended for spectra acquisition has been developed as discussed by the authors.Abstract:
The use of 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane as a phosphitylation reagent in quantitative 31P NMR analysis of the hydroxyl groups in lignins has been thoroughly examined, and an experimental protocol recommended for spectra acquisition has been developed. Quantitative analysis of six “standard lignins” gave results comparable to those obtained by other methods of analysis. Excellent resolution of the various phenolic hydroxyl environments including those present in condensed moieties was observed. However, this was at the expense of resolution in the aliphatic hydroxyl region, where no distinction between primary, secondary, and the erythro and threo forms of the secondary hydroxyls of the ,l?-0-4 bonds can be made.read more
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Catalytic Transformation of Lignin for the Production of Chemicals and Fuels
TL;DR: This paper presents a new state-of-the-art implementation of the iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) Key Laborotary of Catalysis, which automates the very labor-intensive and therefore expensive and therefore time-heavy and expensive process ofalysis.
Journal ArticleDOI
Review of current and future softwood kraft lignin process chemistry
TL;DR: The structure of lignin has remained one of the most difficult biopolymers to characterize, however recent advances in analytical chemistry and spectroscopy have dramatically improved our knowledge of this natural resource as discussed by the authors.
Journal ArticleDOI
Poplar as a feedstock for biofuels: A review of compositional characteristics
TL;DR: In this article, the composition of the key chemical constituents of hybrid poplar species used for bio-fuels is reviewed, with emphasis on lignin struc- ture.
Journal ArticleDOI
A review on lignin-based polymeric, micro- and nano-structured materials
Antoine Duval,Martin Lawoko +1 more
TL;DR: A review of the use of lignin in polymer applications can be found in this paper, where both the direct use of Lignin and the chemical modifications of it are discussed from a polymer chemistry perspective.
Journal ArticleDOI
Characterization of milled wood lignin and ethanol organosolv lignin from miscanthus
Roland El Hage,Nicolas Brosse,Laurent Chrusciel,Christian Sanchez,Poulomi Sannigrahi,Arthur J. Ragauskas +5 more
TL;DR: Ethanol organosolv lignin extracted from Miscanthus giganteus (using the following conditions: T ǫ= −190 à −C, t à = 60 à à min, sulfuric acid à 1.2% w/w, EtOH/H 2 OÞ= 0.65) and milled wood Lignin from MISGAPTEUS were subjected to a comprehensive structural characterization by 13 C, 31 P NMR, FTIR, UV spectroscopies and size exclusion chromatography as discussed by the authors
References
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Journal Article
Studies on finely divided wood. Part 1. Extraction of lignin with neutral solvents
TL;DR: In this paper, it was found that by grinding wood, dispersed in a non-swelling liquid, in a vibrational ball mill, it is possible to extract 50per thousand or more of the lignin from spruce (Picea excelsa ), providing the charge to the mill is small enough.
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Carbon-13 NMR Spectra of Lignins, 8. Structural Differences between Lignins of Hardwoods, Softwoods, Grasses and Compression Wood
TL;DR: The carbon-13 NMR Spectra of four acetylated hardwood MWLs (Acer platanoides, Carpinus betulus, Prunus avium and Quercus robur) were compared with those of dehydrogenation polymers (DHPs) from p-coumaryl alcohol (H- DHP), a Co-DHP obtained from an equimolar mixture of guaiacyl-(G), syringyl-(S) and p-hydroxyphenylpropane (H) units.
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Quantitative phosphorus-31 NMR analysis of lignins, a new tool for the lignin chemist
TL;DR: In this paper, a quantitative method for the determination of the various types of hydroxyl groups present in lignins was developed for determining the syringyl, guaiacyl and p-hydroxyphenyl free phenolic groups.
Journal ArticleDOI
Determination of Hydroxyl Groups in Lignins Evaluation of 1H-, 13C-, 31P-NMR, FTIR and Wet Chemical Methods
TL;DR: Faix et al. as mentioned in this paper evaluated hydroxyl groups in Lignins using -9€-, 9€, 9 FTIR and Wet Chemical Methods and found that hydroxy groups in lignins are more stable than other groups.