Cellulose

DefinitionA natural carbohydrate high polymer (polysaccha- ride) consisting of anhydroglucose units joined by an oxygen linkage to form long molecular chains that are essentially linear. It can be hydrolyzed to glucose. The degree of polymerization is from 1000 for wood pulp to 3500 for cotton fiber, giving a molecular weight from 160,000 to 560,000. Cellulose is a colorless solid, d approximately 1.50, insoluble in water and organic solvents. It will swell in sodium hydroxide solution and is soluble in Schweitzer’s reagent. It is the fundamental con- stituent of all vegetable tissues (wood, grass, cotton, etc.) and the most abundant organic material in the world. Cotton fibers are almost pure cellulose; wood contains approximately 50%. The physical structure of cellulose is unusual in that it is not a single crystal but consists of crystalline areas embedded in amorphous areas. Chemical reagents penetrate the latter more easily than the former. Cel- lulose is virtually odorless and tasteless and is com- bustible, with an ignition point of approximately 450F. In some forms, it is flammable. For example, railroad shipping regulations require a flammable label on such items as burnt fiber, burnt cotton, wet waste paper, and wet textiles. Fires have been known to occur in warehouses in which telephone books were stored. These were undoubtedly due to heat buildup in the paper caused by microbial activity and self-sustaining oxidation.