Wood, cellulose

The question of substituting wood pulp cellulose for cotton as a raw material in the production of nitrocellulose arose at the beginning of the present century due to-the big increase in nitrocellulose manufacture, which was followed by an expansion in the demand for cotton. 

A particularly acute shortage of cotton occurred in Germany during World War I, and wood pulp cellulose was widely used there for nitration, although the product was inferior in quality than that made from cotton. Towards the end of World War I (about 1918), due to the shortage of cotton in the U.S.A. (despite 

Eventually, the problem of using wood cellulose as a nitration material was solved successfully during the interwar period, and during World War n, wood pulp cellulose was commonly used for nitrocellulose manufacture. 

Raw wood contains 45-60% of cellulose. Morphologically this kind of cellulose is distinguished from cotton cellulose by the smaller size of its fibres. Chemically it is more reactive. 

Spruce wood for example consists of the following components  

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Carbon disulphide is an excellent solvent for fats, oils, rubber, sulphur, bromine and iodine, and is used industrially as a solvent for extraction. It is also used in the production of viscose silk, when added to wood cellulose impregnated with sodium hydroxide solution, a viscous solution of cellulose xanthate is formed, and this can be extruded through a fine nozzle into acid, which decomposes the xanthate to give a glossy thread of cellulose. 

Other fibrous and porous materials used for sound-absorbing treatments include wood, cellulose, and metal fibers foamed gypsum or Pordand cement combined with other materials and sintered metals. Wood fibers can be combined with binders and dame-retardent chemicals. Metal fibers and sintered metals can be manufactured with finely controlled physical properties. They usually are made for appHcations involving severe chemical or physical environments, although some sintered metal materials have found their way into architectural appHcations. Prior to concerns regarding its carcinogenic properties, asbestos fiber had been used extensively in spray-on acoustical treatments. 

Cellulose is the main component of the wood cell wall, typically 40—50% by weight of the dry wood. Pure cellulose is a polymer of glucose residues joined by 1,4-P-glucosidic bonds. The degree of polymerization (DP) is variable and may range from 700 to 10,000 DP or more. Wood cellulose is more resistant to dilute acid hydrolysis than hemiceUulose. X-ray diffraction indicates a partial crystalline stmcture for wood cellulose. The crystalline regions are more difficult to hydrolyze than the amorphous regions because removal of the easily hydrolyzed material has Htde effect on the diffraction pattern. 

A commercial bacterial cellulose product (CeUulon) was recently introduced by Weyerhaeuser (12). The fiber is produced by an aerobic fermentation of glucose from com symp in an agitated fermentor (13,14). Because of a small particle diameter (10 P-m), it has a surface area 300 times greater than normal wood cellulose, and gives a smooth mouthfeel to formulations in which it is included. CeUulon has an unusual level of water binding and works with other viscosity builders to improve their effectiveness. It is anticipated that it wiU achieve GRAS status, and is neutral in sensory quaUty microcrystaUine ceUulose has similar attributes. 

DuPont in the U.S. developed about 1909, a smokeless powder from cotton of relatively low nitrogen that was quite soluble in ether alcohol. A small amount of diphenylamine was used as a stabilizer. After forming the grains and removing the liquid, a coating of graphite was added to make the smokeless powder that was used in the U.S. Other double-base types contain about 25% nitroglycerin. Cotton lint for nitration has been replaced by purified wood cellulose. 

Photo-induced grafting onto wood cellulose with several vinyl monomers using phenyl acetophenone and benzophenone derivatives as photosensitizers has been reported [72]. A fast increase in grafting was observed for short irradiation times, whereas longer ones resulted in a decreased percent grafting. 

The surface energy of fibers is closely related to the hydrophilicity of the fiber [38]. Some investigations are concerned with methods to decrease hydrophilicity. The modification, of wood cellulose fibers with stearic acid [43] hydrophobizes those fibers and improves their dispersion in polypropylene. As can be observed in jute-reinforced unsaturated polyester resin composites, treatment with polyvinylacetate increases the mechanical properties [24] and moisture repellency. 

Seven diets were constructed from purified natural ingredients obtained from either C3 (beet sugar, rice starch, cottonseed oil, wood cellulose, Australian Cohuna brand casein, soy protein or wheat gluten for protein) or C4 foodwebs (cane sugar, corn starch, com oil, processed corn bran for fiber, Kenya casein for protein) supplemented with appropriate amounts of vitamins and minerals (Ambrose and Norr 1993 Table 3a). The amino acid compositions of wheat gluten and soy protein differ significantly from that of casein (Ambrose and Norr 1993). 

Tea bag paper is generally made from a mixture of wood cellulose (30 to 40%) and abaca fiber (60 to 70%). The latter is derived from the plant Musa texitilis grown in Madagascar and the Philippines. 

Polglase, W. J., Polysaccharides Associated with Wood Cellulose, X, 283-333... 

Tang, W. K., H. W. Eickner. Effect of Inorganic Salts on Pyrolysis of Wood, Cellulose, and Lignin Determined by Differential Thermal Analysis FPL Research Paper 82, U.S.D.A., 1967. 

The two most important natural pentoses, 1 -arabinose and 1 -xylose, occur in nature as polymeric anhydrides, the so-called pentosans, viz. araban, the chief constituent of many vegetable gums (cherry gum, gum arabic, bran gum), and xylan, in wood. From these pentapolyoses there are produced by hydrolysis first the simple pentoses which are then converted by sufficiently strong acids into furfural. This aldehyde is thus also produced as a by-product in the saccharification of wood (cellulose) by dilute acids. Furfural, being a tertiary aldehyde, is very similar to benzaldehyde, and like the latter undergoes the acyloin reaction (furoin) and takes part in the Perkin synthesis. It also resembles benzaldehyde in its reaction with ammonia (p. 215). 

FIRI I Wood cellulose (Belfast Scots Pine) 0.5722... 

FIRI I Belfast Scots Pine Dendro-dated Wood Cellulose pMC Dr. E. M. Scott, U. Glasgow... 

Bhuiyan, M.T.R., Hirai, N. and Sobue, N. (2000). Changes of crystallinity of wood cellulose by heat treatment under dried and moist conditions. Journal of Wood Science, 46(6), 431 36. 

The fact that EMC reduction as a function of acetyl content is the same for many different llgnocelluloslc materials Indicates that reducing moisture sorption and, therefore, achieving cell wall stability are controlled by a common factor. The lignin, hemlcellulose, and cellulose contents of all the materials plotted in Figure 2 are different (Table II). Earlier results showed that the bonded acetate was mainly in the lignin and hemicelluloses (33) and that Isolated wood cellulose does not react with uncatalyzed acetic anhydride ( 4) ... 

The importance of time, temperature and acid concentration in the hydrolysis of cellulose with dilute acid was recognized by early investigators and applied in the investigations of Simonsen in 1898. Further study was made by Kressman and reported in U. S. Department of Agriculture Bulletin No. 983. Reviews of the quantitative aspects have been made by Doree. Liiers pointed out that the conversion of cellulose dextrin to D-glucose by dilute sulfuric acid was a monomolecular reaction. The constants of the hydrolysis of wood cellulose have been determined by Saeman. The reaction rate (A ) was found to be expressed by the following equation ... 

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