Wood Science and Technology 

About: Wood Science and Technology is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Lignin & Moisture. It has an ISSN identifier of 0043-7719. Over the lifetime, 2650 publications have been published receiving 76865 citations.

Lignin chemistry—past, present and future

Abstract: Some pertinent results and views from the earlier history of lignin chemistry, pointing to the importance of the arylpropane skeleton, are outlined. Later development, beginning with the dehydrogenation theory and experimental studies on the dehydrogenative polymerization of p-hydroxycinnamyl alcohols, is then reviewed. Finally, recent degradative work resulting in a detailed picture of lignin structure is discussed.

Recent progress in the chemistry of wood hemicelluloses

Abstract: Following a brief review of the general chemical composition of wood, the present status of the chemistry of the wood hemicelluloses is summarized, with special emphasis on recent contributions. The distribution of the hemicelluloses in the various wood tissues and wood cells and over the cell wall of tracheids and fibers is discussed in somewhat more detail. In conclusion, problems still to be solved in the chemistry of wood hemicelluloses are mentioned, and an attempt is made to predict future developments in this field.

Lignin biochemistry: Biosynthesis and biodegradation *

Abstract: Lignin biosynthesis via shikimate-cinnamate pathways in plants, and the biosynthetic differences of guaiacyl-and syringyl lignins between gymnosperms and angiosperms have been elucidated by tracer experiments using 14C labeled precursors and the following enzyme reactions. The formation of guaiacyl lignin but not syringyl lignin in gymnosperms was attributed to the following factors; absence of ferulate-5-hydroxylase, poor affinity of O-methyltransferase toward 5-hydroxyferulate, and lack of activation and/or reduction of sinapatc. A mechanism of lignin-carbohydrate complexes formation in wood cell walls was elucidated based on the reaction of the quinone methide of guaiacylglycerol-β-guaiacyl ether with sugars, and the analysis of DHP-polysaccharide complexes. The main cleavage mechanisms of side chains and aromatic rings of lignin model compounds and synthetic lignin (DHP) by white-rot fungi and their enzymes, lignin peroxidase and laccase have been elucidated using 2H, 13C and 18O-labeled lignin substructure dimcrs with 18O2 and H2 18O. Side chains and aromatic rings of these substrates were cleaved via aryl cation radical and phenoxy radical intermediates, in reaction mediated only by lignin peroxidase/H2O2 and laccase/O2.

A critical discussion of the physics of wood–water interactions

Abstract: This paper reviews recent findings on wood–water interaction and puts them into context of established knowledge in the field. Several new findings challenge prevalent theories and are critically discussed in an attempt to advance current knowledge and highlight gaps. The focus of this review is put on water in the broadest concept of wood products, that is, the living tree is not considered. Moreover, the review covers the basic wood–water relation, states and transitions. Secondary effects such as the ability of water to alter physical properties of wood are only discussed in cases where there is an influence on state and/or transition.

Chemical aspects of kraft pulping

Abstract: Kraft pulping is interpreted in chemical terms on the basis of results from extensive qualitative and quantitative model experiments. In essence, the behavior of lignin is explained as a competition between degradation reactions, mainly involving aryl ether cleavage with participation of neighboring groups, and condensation reactions, comprising conjugate addition of carbanions to quinone methide intermediates. The initial phase of technical delignification is tentatively ascribed to the cleavage of α- and β-aryl ether bonds in phenolic lignin units, whereas the cleavage of β-aryl ether bonds in non-phenolic lignin units is considered to be the rate-determining reaction of the bulk phase. The residual phase may possibly be attributed to the rupture of C-C linkages and to aryl ether cleavage without neighboring group participation. Experimental support for these correlations is provided. The interplay of the various lignin reactions, illustrated in a summarizing scheme, explains some known observations in kraft pulping. Attention is drawn to analogies between reactions involved in the degradation of carbohydrates and those reponsible for the degradation of lignin. From the chemical standpoint, therefore, the selectivity of delignification is due to differences in the reactivity of the wood polymers, rather than to differences in the mechanisms of the degradation reactions. This fact explains the limitations of selective delignification.