stearic acid


stearic acid
a colorless, waxlike, sparingly water-soluble, odorless solid, C18H36O2, the most common fatty acid, occurring as the glyceride in tallow and other animal fats and in some animal oils: used chiefly in the manufacture of soaps, stearates, candles, cosmetics, and in medicine in suppositories and pill coatings. Also called octadecanoic acid.
[1825-35]

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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.

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Universalium. 2010.

Look at other dictionaries:

  • Stearic acid — Stearic acid[1] …   Wikipedia

  • Stearic acid — Stearic Ste*ar ic (st[ e]*[a^]r [i^]k), a. [Cf. F. st[ e]arique.] (Physiol. Chem.) Pertaining to, or obtained from, stearin or tallow; resembling tallow. [1913 Webster] {Stearic acid} (Chem.), a monobasic fatty acid, obtained in the form of white …   The Collaborative International Dictionary of English

  • stearic acid — n. 1. a colorless, odorless, waxlike fatty acid, CH3 (CH2) 16COOH, found in many animal and vegetable fats, and used in making candles, stearates, soaps, etc. 2. a commercial mixture of palmitic and stearic acids …   English World dictionary

  • stearic acid — stearino rūgštis statusas T sritis chemija formulė H(CH₂)₁₇COOH atitikmenys: angl. stearic acid rus. стеариновая кислота ryšiai: sinonimas – oktadekano rūgštis …   Chemijos terminų aiškinamasis žodynas

  • stearic acid — n Octadecanoic acid; one of the most abundant fatty acid s found in animal lipids; used in pharmaceutical preparations, ointments, soaps, and suppositories. * * * stea·ric acid stē .ar ik , .sti(ə)r ik n a white crystalline fatty acid C18H36O2… …   Medical dictionary

  • stearic acid — noun Etymology: French stéarique, from Greek stear hard fat Date: 1830 a white crystalline fatty acid C18H36O2 obtained by saponifying tallow or other hard fats containing stearin; also a commercial mixture of stearic and palmitic acids …   New Collegiate Dictionary

  • stearic acid — [ stɪərɪk, stɪ arɪk] noun Chemistry a solid saturated fatty acid obtained from animal or vegetable fats, used in making soap and candles. Origin C19: stearic from Fr. stéarique, from Gk stear tallow …   English new terms dictionary

  • stearic acid — noun a waxy saturated fatty acid; occurs widely as a glyceride in animal and vegetable fats • Syn: ↑octadecanoic acid • Hypernyms: ↑saturated fatty acid …   Useful english dictionary

  • stearic acid — noun a) The most common saturated fatty acid; it is found in all animal and most vegetable oils and fats; it is used in the manufacture of soap etc. b) octadecanoic acid, CH(CH)COOH …   Wiktionary

  • stearic acid — /stiˌærɪk ˈæsəd/ (say stee.arik asuhd) noun a colourless, odourless, insoluble, waxy, carboxylic acid, octadecanoic acid, C17H35–COOH, the glycerides of which are the principal components of animal fats …   Australian English dictionary