Question

Acetate rayon is prepared from.
A.Acetic Acid
B.Glycerol
C.Starch
D.Cellulose

Answer 1

Acetate rayon is prepared by heating cellulose (cotton) with acetic anhydride.

Complete step by step answer:
Acetate rayon is an organic polymer formed by acetylation of all remaining $- OH$ 's of linear cellulose chain. It is a synthetic yarn, filament or fabric composed of a derivative of the acetic ester of cellulose.
Cellulose acetate is manufactured by converting cellulose into a chemical compound of cellulose which is then dissolved in a suitable solvent and spun by evaporating the solvent. Wood pulp & Cotton linters are the most common raw materials for manufacturing acetate rayon. The pre-treated purified cotton linters are fed into an acetylate containing a mixture of acetic anhydride, glacial acetic acid and a small amount of concentrated sulphuric acid. The acetylate consists of a metal tank having a circular door at the top. The door is sealed after adding the mixture of chemicals and cotton linters and a stirrer with blades rotates in the acetylate to mix the ingredients thoroughly. The acetylation reaction is an exothermic reaction. The acetylation reaction is completed in 7-8 hours at 25-3 $^\circ C$ .
Triacetate is formed at this stage and is called the acid dope. Acetic acid, water and sulphuric acid are added during this stage and it stands for 10-20 hours. This is ripening period where partial conversion of acetate groups to hydroxyl groups takes place. The mixture is then diluted with water and stirred continuously when white flakes of acetate rayon get predicated. The flakes are then placed in a centrifuge and the excess water is made to move out. The flakes are then dried. Acetate rayon is manufactured by dry spinning. It is dissolved in a volatile solvent (Acetone) to form dope. This solution is forced through a spinneret into a chamber in which hot air is circulated.
Dried acetate flakes are mixed with three times the weight of acetone in enclosed tanks which are provided with powerful stirrers. The acetate dissolves slowly in the solvent. It takes about a day for the complete dissolution to give a thick clear liquid called dope. Then solution is filtered. The dope is spun into acetate rayon filaments on the dry spinning process and fed into spinning cabinets. The dope coming out of the spinnerets travels a distance of 2-5 meters vertically downwards to a feed roller, from where it is guided on to a bobbin at a much greater speed than the speed of spinning. This imparts twist to the filaments.

Note: Acetate is a composition derived from acetic acid. Rayon is a natural material that is made from the cotton or the cellulose of wood pulp