نتایج جستجو برای: milled wood lignin
تعداد نتایج: 51981 فیلتر نتایج به سال:
Efficient lignin depolymerization is unique to the wood decay basidiomycetes, collectively referred to as white rot fungi. Phanerochaete chrysosporium simultaneously degrades lignin and cellulose, whereas the closely related species, Ceriporiopsis subvermispora, also depolymerizes lignin but may do so with relatively little cellulose degradation. To investigate the basis for selective ligninoly...
Multiblock copolymers of polystyrene (PS) and poly(methyl methacrylate) (PMMA) were investigate for use as a model coupling agent for wood-based polymer composites. The PS-PMMA copolymers with approximately 50/50 composition and 150,000 molecular weight were synthesized using atom transfer radical polymerization. The ability of the copolymers to improve the interfacial properties was evaluated ...
Bio-oil produced from fast pyrolysis of biomass has been investigated as a renewable fuel and as a source of industrial chemicals. The lignin fraction of bio-oil produced from wood in our fast pyrolysis reactor was separated by using only water and methanol with a 25% yield based on bio-oil weight. This separation procedure appears to be of lower cost than the reported extraction procedure usin...
Wood is the most abundant biomass produced by land plants. Dissection of the molecular mechanisms underlying the transcriptional regulation of wood formation is a fundamental issue in plant biology and has important implications in tree biotechnology. Although a number of transcription factors in tree species have been shown to be associated with wood formation and some of them are implicated i...
Brown rot fungi are theorized to use both free radicals and enzymes to degrade wood. If these incompatible agents are employed in sequence (enzymatic after oxidative) in order to avoid interaction, this should be resolvable spatially in rotting wood. To assess this, we used thin spruce wafers as substrates, with the largest face the transverse plane. Propped wafers were colonized from the botto...
To further clarify reasons for formation of condensed residues during the last stage of wood liquefaction in the medium of polyhydric alcohols and sulfuric acid catalyst, the weight loss behaviors and thermal reaction kinetics of condensed residues were studied by thermogravimetric analysis (TGA). Simultaneously, chemical methods were used to analyze the contents of lignin, cellulose, and holoc...
The structure of wood is so compact that enzymes are too large to penetrate into the structure and thereby attack the wood components for modifications that can be valuable for various purposes. Here we present a pretreatment method based on traditional kraft pulping, which opens the wood structure, so that enzymes are able to attack the wood components. To study this kind of chemical pretreatm...
Dynamic (or 2D) FT-IR spectroscopy in combination with polarized IR irradiation has been used in this work to study wood polymer orientation and interactions on the ultrastructural level in wood fibers in the native state as well as the effects of different pulping processes. The wood polymer interactions were studied under both dry and humid conditions. The matrix of lignin and hemicelluloses ...
Brown-rot fungi are Basidiomycetes that remove cellulose and other polysaccharides from wood, leaving an amorphous, brown, crumbly residue that is composed largely of lignin, hence the name brown-rot. Decay by brown-rot fungi is by far the most serious type of damage to wood in-service. These fungi cause structural failure before losses in total wood substance are detected. The effect of brown-...
In this thesis, wood nanotechnologies for transparent, fire-retardant and hydrophobic/lipophilic wood have been developed. There are two main parts; wood template preparation/processing concepts and materials design using these templates. In the wood template processing part, highly porous nanostructured wood templates are prepared. Relationships between processes and material structures are st...
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