Biopolymers lignins

Hatakka A (2001) In Hofrichter M, Steinbiichel A (eds) Biopolymers lignin, humic substances and coal, 1st edn. Wiley-VCH, Weinheim, p 129... 

Figure 15.3. Overlaid HSQC spectra of biopolymers on IHSS peat. (A) Biopolymers lignin (gray), amylopectin (red), albumin (blue) and cuticle (green) overlaid on each other. (B) All biopolymers are illustrated in black. (C) IHSS humic acid extract from peat. (D) Biopolymers (black) overlaid on IHSS peat (green). The highlighted areas in 2D are those not well represented by biopolymers in the HA, namely complex carbohydrates and p- ydroxybcnzoatcs from lignin [see Kelleher and Simpson (2006) for more details]. See color insert. Reprinted from Kelleher, B. R, and Simpson, A. J. (2006). Humic substances in soils Are they really chemically distinct Environ. Sci. Technol. 40,4605-4611, with the permission of the American Chemical Society.

Hatakeyama H., Hatakeyama T. Lignin structure, properties and applications. In Abe A., Dusek K., Kobayashi S. (eds.) Biopolymers. Lignin, Proteins, Bioactive Nanocomposites, vol. 232, pp. 1-63. Springer, Berlin, Adv. Polym Sci. (2010)... 

M. Hofrichter and A. Steinbiichel, Biopolymers Lignin, Humic Substances and Coal, Wiley-VCH, 2001. 

Biopolymers Lignin, humus Cellulose, starch, chitin, pullulan, zein... 

Abe A, Dusek K, Kobayashi S. Biopolymers lignin, proteins, bioactive nanocomposites. Springer Science Business Media August 29, 2010. 214 pages. 

Hatakka, A. (2001). Biodegradation of hgnin. In Hoffichter, M., Steinbu chel, A. (Eds.), Biopolymers. Lignin, Humic Substances and Coal, vol. 1. Whey-VCH, Germany, pp. 129-180. 

Synthetic examples include the poly(meth)acrylates used as flocculating agents for water purification. Biological examples are the proteins, nucleic acids, and pectins. Chemically modified biopolymers of this class are carboxymethyl cellulose and the lignin sulfonates. Polyelectrolytes with cationic and anionic substituents in the same macromolecule are called polyampholytes. 

Wood is a composite material that is made, up basically of a mixture of three main constituents, cellulose, hemicellulose, and lignin (see Textbox 54), all of them biopolymers synthesized by the plants, which differ from one another in composition and structure (see Textbox 58). The physical properties of any type of wood are determined by the nature of the tree in which the wood grows, as well as on the environmental conditions in which the tree grows. Some of the properties, such as the density of wood from different types of trees, are extremely variable, as can be appreciated from the values listed in Table 71. No distinctions as to the nature of a wood, whether it is a hardwood or a softwood, for example, can be drawn from the value of its specific gravity. 

The whole of a multi-cellular organism is contained by outer cell layers, which are described in biology texts, and maintained by connective tissue. Connective tissue is a novel, external biopolymer structure of multi-cellular organisms found within their new extracellular, circulating fluid compartments (see Section 8.9). As mentioned there, the main connective tissues, covalently cross-linked structures, are (1) those of plants, celluloses (polysaccharides), often cross-linked by lignin (2) those of lower animals and insects, mixed cross-linked polysaccharides and... 

Pyrolysis of biomass is defined as the chemical degradation of the biopolymers (cellulose, lignin and hemicellulose) constituting the wood fuel which initially requires heat. As can be seen in Figure 51, all reaction pathways making up the pyrolysis are not endothermic, which implies that some of the pyrolysis reactions generate heat. However, overall the pyrolysis process is endothermic. 

Complex pyrolysis chemistry takes place in the conversion system of any conventional solid-fuel combustion system. The pyrolytic properties of biomass are controlled by the chemical composition of its major components, namely cellulose, hemicellulose, and lignin. Pyrolysis of these biopolymers proceeds through a series of complex, concurrent and consecutive reactions and provides a variety of products which can be divided into char, volatile (non-condensible) organic compounds (VOC), condensible organic compounds (tar), and permanent gases (water vapour, nitrogen oxides, carbon dioxide). The pyrolysis products should finally be completely oxidised in the combustion system (Figure 14). Emission problems arise as a consequence of bad control over the combustion system. 

Humic substances A series of relatively high-molecular-weight, yellow- to black-colored substances formed by secondary synthesis reactions. The term is used as a generic name to describe the colored material or its fractions obtained on the basis of solubility characteristics. These materials are distinctive to the soil (or sediment) environment in that they are dissimilar to the biopolymers of microorganisms and higher plants (including lignin)... 

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