The topochemical distribution of lignin and phenolic extractives in woody tissue was determined at a cellular level using scanning UV microspectrophotometry (UMSP). This improved analytical technique enables direct imaging of lignin distribution within individual cell wall layers with a resolution of 0.25 μm. The technique is based on the ultraviolet illumination of semi-thin transverse section...

Woody tissues consist primarily of a mixture of cellulose, hemicelluloses, and lignin. Covalent bonds between lignin and polysaccharides likely play a central role in determining the mechanical and physical properties of wood. Intact and defined lignin-polysaccharide networks have not been isolated in large quantities because of the recalcitrance of lignin, which demands harsh chemical treatmen...

Colonization of wood blocks by brown and white rot fungi rapidly resulted in detectable wood oxidation, as shown by a reduced phloroglucinol response, a loss of autofluorescence, and acridine orange (AO) staining. This last approach is shown to provide a novel method for identifying wood oxidation. When lignin was mildly oxidized, the association between AO and lignin was reduced such that stai...

Technical soda lignin dissolved in urea as an environmental friendly binder in wood fiberboard Hongli Zhu, Yuanyuan Li, Bert Pettersson, Liming Zhang, Mikael Lindström & Gunnar Henriksson To cite this article: Hongli Zhu, Yuanyuan Li, Bert Pettersson, Liming Zhang, Mikael Lindström & Gunnar Henriksson (2014) Technical soda lignin dissolved in urea as an environmental friendly binder in wood fib...

This study was carried out to determine the effect of thinning on density, extractives and lignin content of Pinus nigra Amold tree. Wood density was measured with computed tomography and 540+/-20 kg m(-3) were determined on control samples. Density of samples from thinning applied plot was 520+/-20 kg m(-3). The results showed that thinning slightly changes the density of wood and this change ...

Tension wood, a tissue developed by angiosperm trees to actively recover their verticality, has long been defined by the presence of an unlignified cellulosic inner layer in the cell wall of fibres, called the G-layer. Although it was known that some species have no G-layer, the definition was appropriate since it enabled easy detection of tension wood zones using various staining techniques fo...

Wood pyrolysis for Casuarina glauca, Casuarina cunninghamiana, Eucalyptus camaldulensis, Eucalyptus microtheca was made at 450°C with 2.5°C/min. in a flowing N2-atmosphere. The Eucalyptus genus wood gave higher values of specific gravity, ash , total extractives, lignin, N2-liquid trap distillate (NLTD) and water trap distillate (WSP) than those for Casuarina genus. The GHC of NLTD was higher f...

Severe suppression of 4-coumarate-coenzyme A ligase (4CL) in the coniferous gymnosperm Pinus radiata substantially affected plant phenotype and resulted in dwarfed plants with a "bonsai tree-like" appearance. Microscopic analyses of stem sections from 2-year-old plants revealed substantial morphological changes in both wood and bark tissues. This included the formation of weakly lignified trach...

Wood and dietary fiber products all belong to a class of biomolecular composites that are rich in cellulose and lignin. The interaction between cellulose and lignin determines such properties as mechanical strength (wood); creep, durability and aging; cellulose purity (pulp); and digestibility (nutrients). The understanding of the interaction between cellulose and lignin can be approached from ...

Three different milled lignins isolated from bamboo, pine and beech, corresponding to the three different structural groups, have been subjected to pyrolysis in the presence of tetramethylammonium hydroxide (TMAH) and tetrabutylammonium hydroxide (TBAH). Pyrolysis of the lignins in the presence of TMAH releases the methyl esters and methyl ethers of the different lignin monomers. Several moieti...