CELLULOSE ACETATE, a thermoplastic resin of cellulose. Fibers made of cellulose acetate are widely used in the production of a strong, silklike material that is easily dyed and wears well. The resin is also used in lacquers, protective coatings, artificial leather, transparent sheeting, and cigarette filters and in the production of plastics and acetate film.
Cellulose acetate occurs as odorless white flakes or as a powder; it softens at temperatures of from 60° to 97° C (140° to 207° F) and melts at about 260° C (500° F). It is soluble in acetone, ethylene dichloride, ethyl acetate, cyclohexanol, and nitropropane.
Cellulose acetate is produced by treating cellulose from wood pulp or cotton with acetic acid and acetic anhydride in the presence of sulfuric acid. The product of this reaction, which is ace-tylated cellulose, is then partially hydrolyzed. In the final product, each of the glucose subunits of the cellulose contains an average of 2 to 2.5 acetate groups.
Fibers of cellulose acetate are made by forc-ing an acetone solution of the compound through small openings in a spinneret into a warm-air stream, which causes the solvent to evaporate from the filaments. In the production of cellulose acetate films, the solution is coated on a drum, and when the solvent evaporates, the remaining film is removed. The films are used as a support for photographic film, for magnetic tape for sound recording, for packaging, and for laminating.
For use as a plastic, cellulose acetate is usu-ally combined with plasticizers and dyes or pig-ments. The plastics are tough and have a high mechanical strength and relatively low flammability. They are widely used in handles for tools and cutlery, in toys, and in containers for radios and other appliances.