Lignin components

Sodium chlorite has also been used for treatment and removal of toxic and odorous gases such as hydrogen sulfide and mercaptans. Chlorine dioxide from chlorite is also useful for microbial and slime control in paper mills and alkaline paper machine systems (164,165). The use of sodium chlorite in textile bleaching and stripping is well known. Cotton is not degraded by sodium chlorite because the oxidation reactions are specific for the hemiceUulose and lignin components of the fibers. 

Dietary fiber and fiber-rich food fractions bind bile acids and bile salts in vitro. This interaction is more pronounced for the lignin component. 

An alternative possibility is that of the biorefinery. In this concept a few key chemicals would be isolated from a small number of process steps. Whilst there are many possibilities for this, in one example the raw material, say com, could be cmshed to release oil (the first key product). The resulting mass could then be fermented to give several key platform chemicals such as ethanol, lactic acid and acetic acid. This attractive concept would be more viable if all the cellulose and lignin components could be efficiently used in the fermentation process. 

Other spherical fillers include carbon black. This has several roles particularly in combination with elastomers, e.g., black pigment, anti-oxidant and UV stabiliser, reinforcing filler, and an electrical conductor when used at 60% concentration. Wood flour is particularly effective in phenol/formaldehyde and melamine or urea/formaldehyde thermoset resins because the phenolic lignin component in the wood reacts with the methylol groups (-CH2OH) in the growing polymer. 

Kogel, I. (1986). Estimation and decomposition pattern of the lignin component in forest humus layers. Soil Biology and Biochemistry 18 589-594. 

Two Streptomyces strains, S. badius and S. viridosporus, were found to be able to grow on kraft lignin (In-dulin ATR) as sole carbon source. The resulting APPL (Acid Precipitable Polymeric Lignin) was characterized by FTIR and elemental analysis for C, H and N, and was found to contain proteins in addition to a relatively demethoxylated lignin component. The proteins were further characterized by amino acid analysis, while the lignin component was separated by solvent extraction and its molecular weight distribution determined by HPSEC. 

Its nature as a lignin component is confirmed by its elemental composition and IR-spectrum compared with corresponding data for a milled wood lignin preparation, Table I and Figure 12. 

Fractionation on Sephadex G-25 using 0.5M sodium hydroxide as eluent causes the low molar mass lignin components in black liquor to elute in the relative retention volume range 0.3-1.3 with partial separation from each other, as shown in Figure 11. 

Figure 11. Fractionation of low molar mass lignin components in kraft black liquor. Column Sephadex G-25. Eluent 0.5M NaOH.

Modes of Association Between Kraft Lignin Components... 

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