Structural Analysis of Residual and Technical Lignins by 1H-13C Correlation 2D NMR-Spectroscopy

Holzforschung ◽  
2001 ◽  
Vol 55 (3) ◽  
pp. 302-308 ◽  
Author(s):  
Ewellyn A. Capanema ◽  
Mikhail Yu Balakshin ◽  
Chen-Loung Chen ◽  
Josef S. Gratzl ◽  
Hanna Gracz
Keyword(s):  
Structural Analysis ◽  
Eucalyptus Globulus ◽  
2D Nmr ◽  
Kraft Lignin ◽  
Coniferyl Alcohol ◽  
Spectroscopic Techniques ◽  
Carbonyl Groups ◽  
2D Nmr Spectroscopy ◽  
Organosolv Lignin ◽  
Technical Lignins

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.

Rigid polyurethane foams from unrefined crude glycerol and technical lignins

2018 ◽  
Vol 9 (3-4) ◽  
pp. 111-132 ◽  
Author(s):  
Louis Christiaan Muller ◽  
Sanette Marx ◽  
Hermanus CM Vosloo ◽  
Elvis Fosso-Kankeu ◽  
Idan Chiyanzu
Keyword(s):  
Crude Glycerol ◽  
Thermal Characteristics ◽  
Kraft Lignin ◽  
Polyurethane Foams ◽  
Pulp And Paper ◽  
Rigid Polyurethane Foam ◽  
Organosolv Lignin ◽  
Green Materials ◽  
By Products ◽  
Technical Lignins

The need for green materials has driven interest in the preparation of rigid polyurethane foam (PUF) from various biomass types. The present study aims at increasing bio-based content by utilizing by-products from both the pulp and paper and biodiesel industries. Bio-based polyols from respective liquefaction of kraft lignin, organosolv lignin and lignosulphonate in crude glycerol were employed to prepare rigid PUFs. The highest foam compressive strength was 345 kPa with density 79 kg m−3; thermal conductivity was 0.039 W m−1 K−1 and the corresponding material had 44 wt% renewable content. Thermal characteristics and biodegradability were also evaluated. Technical lignin type was found to determine product properties to a large extent. Based on the use of existing industrial scale by-products in this study, the findings can be beneficial for present and future biorefineries in the valorization of lower value by-product streams.

Synthesis of the 4-Pyridine Analog of Kostanecki's Triketone. Determination of Constitution and Stereochemistry by 2D-NMR Spectroscopy and X-ray Structural Analysis

1991 ◽  
Vol 1991 (12) ◽  
pp. 1337-1341 ◽  
Author(s):  
Horst Kessler ◽  
Siggi Mronga ◽  
Bernhard Kutscher ◽  
Arndt Müller ◽  
William S. Sheldrick
Keyword(s):  
Nmr Spectroscopy ◽  
Structural Analysis ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
X Ray

scholarly journals Selective modification of the β–β linkage in DDQ-treated Kraft lignin analysed by 2D NMR spectroscopy

2015 ◽  
Vol 17 (1) ◽  
pp. 244-249 ◽  
Author(s):  
F. Tran ◽  
C. S. Lancefield ◽  
P. C. J. Kamer ◽  
T. Lebl ◽  
N. J. Westwood
Keyword(s):  
Nmr Spectroscopy ◽  
2D Nmr ◽  
Kraft Lignin ◽  
2D Nmr Spectroscopy ◽  
Selective Transformation

Analysis of the selective transformation of the β–β linkage in Kraft lignin using readily accessible 2D HSQC NMR protocols.

scholarly journals Comparison of four technical lignins as a resource for electrically conductive carbon particles

BioResources ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 1091-1109 ◽  
Author(s):  
Janea Köhnke ◽  
Notburga Gierlinger ◽  
Batirtze Prats-Mateu ◽  
Christoph Unterweger ◽  
Pia Solt ◽  
...  
Keyword(s):  
Composite Films ◽  
Particle Morphology ◽  
Major Effect ◽  
Kraft Lignin ◽  
High Mass ◽  
Carbon Particles ◽  
Organosolv Lignin ◽  
High Mass Loss ◽  
Soda Lignin ◽  
Technical Lignins

Carbon microparticles were produced from different technical lignins, i.e., kraft lignin, soda lignin, lignosulfonate, and organosolv lignin, at different carbonisation temperatures (800 °C, 1200 °C, 1600 °C, and 2000 °C). Before carbonisation, oxidative thermostabilization was performed. The combination of thermostabilization and carbonisation led to a high mass loss and shrinkage, but no major effect on the particle morphology was apparent. The carbon particles obtained from all four lignin variants developed disordered graphitic structures at high carbonisation temperatures, and good electrical conductivities in the carbon powders were observed for all lignin variants, with the exception of lignosulfonate. The polycaprolactone composite films filled with 30% lignin-derived carbon exhibited various conductivities, with the best results achieved using the kraft lignin-derived carbon.

Fusiformines A and B: new indole alkaloids from Melodinus fusiformis

2016 ◽  
Vol 71 (3) ◽  
pp. 193-195 ◽  
Author(s):  
Yong-chao Li ◽  
Jing Yang ◽  
Xiu-ren Zhou ◽  
Xin-hong Liang ◽  
Qing-yun Fu
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Indole Alkaloids ◽  
2D Nmr ◽  
Spectroscopic Techniques ◽  
2D Nmr Spectroscopy ◽  
Monoterpenoid Indole Alkaloids

AbstractFusiformines A (1) and B (2), two new monoterpenoid indole alkaloids, were isolated from the twigs and leaves of Melodinus fusiformis. Their structures were established by extensive spectroscopic techniques, including 2D NMR spectroscopy and mass spectrometry.

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