stearic

Stearic, in chemical terms, refers to stearic acid, a saturated long-chain fatty acid with 18 carbon atoms and the formula C18H36O2. It occurs naturally in both animal fats (such as tallow and lard) and plant fats (including cocoa butter, shea butter, and palm kernel oil). Stearin is also used to describe the solid fraction of fats, from which stearic acid can be isolated.

Physical and chemical properties include a white, waxy solid at room temperature with a melting point around 69 to 70°C. It is insoluble in water and dissolves in many organic solvents. As a carboxylic acid, it forms salts with bases to give metal or alkali stearates (for example, sodium stearate and calcium stearate), which are important in soaps and lubricants. Stearic acid can be obtained by hydrolysis (saponification) of fats and oils and is then purified; it can also be produced by hydrogenation of unsaturated fats to increase its saturated content.

Production and sources: stearic acid is a major component of the fatty acid profile of many fats and oils. In industrial settings, oleochemicals derived from animal or vegetable fats are fractionated to enrich the stearin fraction, and further processing yields stearic acid for commercial use. It is widely produced in the oleochemical industry and used as a building block for various derivatives.

Uses and applications: stearic acid and its salts are used in soaps, detergents, cosmetics (as an emollient and thickener), candles, and lubricants. It also serves as a lubricant and release agent in polymer and rubber processing and as a starting material for producing soaps and surfactants. Safety considerations are minimal under normal handling, though concentrated products can be irritant.