请输入您要查询的百科知识:

 

词条 stearic acid
释义
stearic acid
chemical compound
also called Octadecanoic Acid,
one of the most common long-chain fatty acids, found in combined form in natural animal and vegetable fats. Commercial “stearic acid” is a mixture of approximately equal amounts of stearic and palmitic acids and small amounts of oleic acid. It is employed in the manufacture of candles, cosmetics, shaving soaps, lubricants, and pharmaceuticals.
In nature stearic acid occurs primarily as a mixed triglyceride, or fat, with other long-chain acids and as an ester of a fatty alcohol. It is much more abundant in animal fat than in vegetable fat; lard and tallow often contain up to 30 percent stearic acid.
Alkaline hydrolysis, or saponification, of fats yields soaps (soap and detergent), which are the sodium or potassium salts of fatty acids; pure stearic acid is obtained with difficulty from such a mixture by crystallization, vacuum distillation, or chromatography of the acids or suitable derivatives. The pure acid undergoes chemical reactions typical of carboxylic acids. It is a colourless, waxy solid that is almost insoluble in water.
随便看

 

百科全书收录100133条中英文百科知识,基本涵盖了大多数领域的百科知识,是一部内容开放、自由的电子版百科全书。

 

Copyright © 2004-2023 Newdu.com All Rights Reserved
更新时间:2025/6/26 1:58:07