Explanation

adopt β- A linear natural polymer formed by the binding of 1,4-glycosidic bonds is the main component of plant cell walls and one of the most abundant and widely distributed organic compounds on Earth. cellulose exists in many plants and wastes, among which cotton has the highest content, up to 95% to 99%; Wood contains 40% to 50% cellulose; The stems of rice, wheat straw, bamboo, reed, etc. contain 10% to 50% cellulose; The phloem of ramie, etc. contains 80% to 90% cellulose. cellulose can also be found in algae, bacteria and animal skins. The density of natural cellulose is about 1.60 g/cm 3， The degree of polymerization is usually between 1000 and 15000, the molecular weight distribution is relatively dispersed, its chemical properties are very stable, and it is insoluble in water and general organic solvents. Under acidic conditions, cellulose will be decomposed into monosaccharides, while under strong alkaline conditions, cellulose will be liquefied. The dissolution of cellulose usually requires special solvents, such as metal amine solvent, iron sodium tartrate solvent and some non-aqueous solvents. The crystallinity of natural cellulose is usually between 80% and 90%, which plays a decisive role in its physical chemistry properties. Natural cellulose (such as cotton and flax) is mainly used as fabric raw material. In addition, after chemical treatment, cellulose can be made into nitrocellulose, cellulose acetate, xanthate cellulose, etc. These products are widely used to manufacture man-made fibers, coatings, films, printed circuit boards, electrical insulation materials, plastics, explosive, etc. cellulose can also be hydrolyzed to produce glucose, which can be used in fermentation and other processes to prepare yeast, ethanol, synthetic resin, amino acids and other raw materials. Wood is also rich in cellulose, so it is widely used in paper making and chemical machining.

Classification