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Contribution of Extractives to Wood Characteristics

The major components of wood are cellulose, hemicelluloses, and lignin, and many of the properties of wood are a function of this lignocellulosic network. Although extractives are a minor component, often constituting less than lO o of the wood, they contribute disproportionately to the characteristics of wood. It is extractives that give wood its color, its odor, and, to some extent, its physical properties. Extractives can have a significant influence on how wood is used. [Pg.843]


The relationship of modern wine styles to aging wines in wooden barrels is described. The physical and chemical characteristics of different woods lead to the conclusion that white oak is best for wine cooperage. European cooperage oak samples had 161% of the extractable solids of North American samples and 154% of the phenol per unit of extractable solids, but American oak contributed more oak flavor to wine per unit of extract. Data are presented on the density and extractable phenol content of summer and spring oak wood, the characteristics of rapidly vs. slowly grown oak, the surface per unit volume effects of container size and shape, the variability among trees in flavor and extract content, the analysis of wood extract in wine, and the depth of penetration of wine into staves. [Pg.261]

Cellulose nanofibers from different sources have showed remarkable characteristics as reinforcement material for optically transparent composites [160, 161], Iwamoto et al. [160] prepared optically transparent composites of transparent acrylic resin reinforced with cellulose nanofibers extracted from wood pulp fibers by fibrillation process. They showed that cellulose nanofiber-reinforced composites are able to retain the transparency of the matrix resin even at high fiber content (up to70 % wt). The aggregation of cellulose nanofibers also contributes to a significant improvement in the thermal expansion properties of plastics. [Pg.43]

In the sixteenth and early seventeenth centuries, the distillation and extraction of plant and animal materials were the characteristic chemical operations of pharmacy. The focus of chemical-pharmaceutical practice was on the extraction of oils and juices and on the distillation of aqueous and oily substances from plants or vegetable materials such as herbs, blossoms, fruits, seeds, woods, resins, and balsams. However, in the sixteenth century Paracelsus and his followers began to use more frequently minerals as a source of medicines in addition to vegetable and animal substances. What was at first only a sporadic production of new chemical prepara-tions eventually induced a fundamental change in pharmacy. During the seventeenth century, preparations of mineral acids and salts surfaced as an important sector of chemical-pharmaceutical practice. This new commercial chemical practice spurred a process of reflection that contributed to the formation of the modem concept of the chemical compound. [Pg.142]


See other pages where Contribution of Extractives to Wood Characteristics is mentioned: [Pg.843]    [Pg.845]    [Pg.847]    [Pg.849]    [Pg.851]    [Pg.853]    [Pg.855]    [Pg.857]    [Pg.859]    [Pg.843]    [Pg.845]    [Pg.847]    [Pg.849]    [Pg.851]    [Pg.853]    [Pg.855]    [Pg.857]    [Pg.859]    [Pg.1155]    [Pg.181]    [Pg.375]    [Pg.375]    [Pg.279]    [Pg.426]    [Pg.184]    [Pg.375]    [Pg.54]   


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Extraction of wood

Of woods

Wood characteristics

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