Cellulose-containing materials

Cut the cellulose-containing material into very small pieces (so as not to clog the blender). 

Powerful oxidants are particularly dangerous when mixed with easily oxidised organic substances such as simple alcohols, polyhydric alcohols, carbohydrates and cellulose-containing materials such as paper, cloth or wood. They are also dangerous when mixed with elements such as sulphur and phosphorus, and with finely divided metals such as magnesium powder. The following are common examples ... 

In principle the anionic dyes also include direct dyes, but, because of their characteristic structures, these are used to dye cellulose-containing materials and are applied to the fiber from a neutral dye bath (see Section 3.3). 

G. Metabolic Difference. Micro-organisms attack wood by secreting enzymes into the immediate structure which in turn break down the wood components into small, soluble units that become nutrients for the organism. The main destructive enzyme system the wood-rotters contain is a class of proteins known as cellulases. These enzymes break down he polymeric cellulose, the strong backbone of wood, into digestible units. Humans do not possess this enzyme system consequently, we cannot degrade cellulose-containing materials. 

Acidity has long been recognized as a major factor contributing to the deterioration of cellulose-containing materials. In an effort to combat the harmful influence of acidity, researchers have developed a variety of deacidification techniques capable of decreasing the acid content of most paper-containing objects that are found in museums and libraries. These techniques often are used by conservators in the care of books and works of art on paper (I). Nevertheless, the nature of the chemical processes that cause papers to yellow and to lose strength remains somewhat obscure, and the role of acidity in these processes also is not well understood. 

The preferred feedstock for chemical activation (see Fig. 5.7-1) is wood, in the form of sawdust. These processes are based on the dehydration of the feedstock by reaction with dehydration agents and are particularly effective with cellulose-containing materials. Chemicals such as phosphoric acid or zinc chloride are utilized. Sawdust is mixed with phosphoric acid or zinc chloride, optionally formed, and then heated to 400 to 600°C when phosphoric acid is utilized or to 600 to 700°C when zinc chloride is utilized. 

There are three major processes which reduce raw material, i.e. any of the cellulose-containing materials mentioned above, to pulp ... 

Manufacture of Alcohol from Cellulose-Containing Material. ... 

Manufacture of Pressware from Cellulose-Containing Materials... 

The portion of cellulose containing material that does not dissolve in 17.5% NaOH at 20°C is the cellulose, known as true cellulose. On acidification of the extract p-ceUulose gets precipitated out, whereas the portion that dissolves in base but does not precipitate out oti acidificadmi is a y-cellulose. 

Alen R. Conversion of cellulose-containing materials into usefijl products. In Kennedy JF, Phillips GO, Williams PA, editors. Cellulose sources and exploitation - industrial utilization, biotechnology, and physicochemical properties. Chichester (England) EUis Horwood 1990.p. 453-64. 

Cotton is almost pure cellulose. Both rayon and acetate rayon are made from chemically modified cellulose and were the first commercially important synthetic textile fibers. In the production of rayon, cellulose-containing materials are treated with carbon disulfide, CSj, in aqueous sodium hydroxide. In this reaction, some of the —OH groups on a cellulose fiber are converted to the sodium salts of a xanthate ester, which causes the fibers to dissolve in alkali as a viscous colloidal dispersion. 

Table 1.2 Chemical composition of some typical cellulose-containing materials...

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