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Extractive Components of Wood Barbara Cole University of Maine

Extractive Components of Wood Barbara Cole University of Maine. Major Components of Wood. Wood Extractives. - Non-cell wall components Can be removed using solvents, e.g. pet. ether, acetone, ethanol, water - Relatively small molecules (< C 40 ) - Usually comprise 1-5% of the wood

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Extractive Components of Wood Barbara Cole University of Maine

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  1. Extractive Components of Wood Barbara Cole University of Maine

  2. Major Components of Wood

  3. Wood Extractives • - Non-cell wall components • Can be removed using solvents, • e.g. pet. ether, acetone, ethanol, water • - Relatively small molecules (< C40) • - Usually comprise 1-5% of the wood • - Under genetic control  vary by species

  4. Lipid Extractive Components I. Aliphatics Fatty acids: <0.1% Fats (fatty acid esters of glycerol): 0.3-0.4%

  5. Fatty alcohols (C16-C28): Waxes (esters of other alcohols): Fatty acid Alcohol Suberin (polyester): n= 18-28

  6. Lipid Extractive Components II. Terpenoids: primarily in softwood species Monoterpenes (C10) Uses: Turpentine, flavor and fragrance chemicals

  7. Lipid Extractive Components II. Terpenoids: primarily in softwood species Diterpenes (C20) (0.2-0.8% of wood) Uses: Rosin, sizing agents

  8. Lipid Extractive Components II. Terpenoids: Triterpenes (C30) (5-30% in birch bark)

  9. Phenolic Extractive Components I. Simple Phenolics

  10. Phenolic Extractive Components II. Stilbenes Stilbenes are generally very toxic! Primarily in the heartwood of conifers.

  11. Phenolic Extractive Components III. Flavonoids • - Flavonoids are the most abundant phenolics. • Coloration in foliage and flowers, astringent taste in unripe fruits. • Condensed tannins: tanning agents, adhesives

  12. Phenolic Extractive Components IV. Lignans Generally non-toxic and are very good antioxidants.

  13. Other Extractive Components • Alkanes • Proteins • Monosaccharides and derivatives

  14. Summary • - Extractive components are “small” molecules that can be • extracted with a solvent from wood, bark, or foliage. • Generally, extractives are present in small amounts. • Extractives vary tremendously within species, between • species, and within trees. • There are thousands of different extractives present in • wood.

  15. Softwoods vs. Hardwoods Softwoods: - Resin acids: 40-45% of extractives - Fatty acids: 40-60% - Monoterpenes (turpentine) - Phenolics Hardwoods: - No resin acids or monoterpenes - Fatty acids: 60-90% - Phenolics

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