Stearic acid also
called octadecanoic acid CH3(CH2)16COOH
is one of the many useful types of saturated
fatty acids that comes from many animal and vegetable
fats and oils. It is a waxy solid that melts at around
70°C and its chemical formula is . Its name comes
from the Greek word, stear, which means tallow.
Stearic acid is prepared by treating animal fat with water at a high pressure and temperature. It can also be obtained from the hydrogenation of vegetable oils. Stearic acid is useful as an ingredient in making candles, soaps, and cosmetics and for softening rubber.
Stearic acid is noteworthy as the most common saturated fatty acid, another common one being the C16 compound palmitic acid.