8804. Stearic Acid

Nomenclature

CAS number: 57-11-4
Octadecanoic acid; Emersol 132 (Emery).
C18H36O2; mol wt 284.48.
C 76.00%, H 12.76%, O 11.25%.

Description and references

Occurs as a glyceride in tallow and other animal fats and oils, as well as in some vegetable oils; also prepd synthetically by hydrogenation of cottonseed and other vegetable oils.

Chemical structure

Properties

White leaflets. d70 0.847; mp 69-70°; bp 383°; nD80 1.4299. Slowly volatilizes at 90-100°. Very slightly sol in water. One gram dissolves in 21 ml alcohol, 5 ml benzene, 2 ml chloroform, 26 ml acetone, 6 ml carbon tetrachloride, 3.4 ml carbon disulfide; also sol in amyl acetate, toluene. LD50 i.v. in mice, rats: 23±0.7, 21.5±1.8 mg/kg, L. Or, A. Wretlind, Acta Pharmacol. Toxicol. 18, 141 (1961). U.S.P. stearic acid consists chiefly of a mixture of stearic and palmitic acids. It is in the form of white or slightly yellow, crystal masses, or a white to slightly yellow powder; slight tallow-like odor. Does not congeal below 54°.

Derivative

Ethyl ester.

Nomenclature

CAS number: 111-61-5
Ethyl stearate.
C20H40O2; mol wt 312.53.
C 76.86%, H 12.90%, O 10.24%.

Properties

White, cryst solid; odorless or practically so. mp 33-35°. bp 224°. Ethyl stearate of commerce solidifies at 20-24°; bp4 180°. Insol in water; sol in alcohol or ether.

Derivative

Methyl ester.

Nomenclature

CAS number: 112-61-8
Methyl stearate.
C19H38O2; mol wt 298.50.
C 76.45%, H 12.83%, O 10.72%.

Properties

White crystals. mp 38-39°. bp15 215°. Insol in water; sol in alcohol, ether.

Use

For suppositories, coating enteric pills, ointments, and for coating bitter remedies. Manuf stearates of aluminum, zinc, and other metals, stearin soap for opodeldoc, candles, phonograph records, insulators, modeling compds; impregnating plaster of Paris; in vanishing creams and other cosmetics.