Stearic acid is a high-level saturated fatty acid, purely made of white soft tablets with gloss. The relative density is 0.9408 (20℃), melting point 69-71℃, boiling point 383℃, and refractive index is 1.4299 (80℃).
Its industrial products are white or slightly yellow granular, a mixture of stearic acid and palmitic acid, and contain a small amount of oleic acid, with a slight butter-like smell. Very slightly soluble in cold water, easily soluble in benzene, toluene, chloroform, carbon tetrachloride, carbon disulfide, amyl acetate, etc., and also soluble in ethanol and acetone. Industrial products are divided into first-grade products (or type 200, formerly known as triple-pressure stearic acid, which has been pressed three times), second-grade products (or type 400, formerly known as double-grade stearic acid, which has been pressed two times) and third-grade products (or type 800, which has been pressed one time or not). The primary and secondary products are white waxy solids, while the third grade products are light yellow waxy solids. Stearic acid is rarely found alone in nature and often exists in the form of glycerides, such as glyceryl tristearate, which is found in most oils and fats of animals and plants, especially butter, which is the most abundant. Stearic acid is an organic acid that can work with alkali to produce sodium stearate and is a soap.
Stearic acid is widely used. In the cosmetics industry, it is an indispensable raw material for the production of general emulsified products. It is used to prepare sauce cream, cold cream, foundation cream, shaving cream, hair cream and skin care lotion. In the rubber industry, it is a vulcanizing active agent for natural glue, synthetic glue and latex, and is also used as a softener. It is used as a plasticizer, stabilizer and lubricant in the plastics industry. It is used as a yarn lubricant and a softener for mercerizing paste in the textile industry. It is also used to manufacture mold release agents, polishing pastes, defoaming agents, metal flotation agents, paint flattening agents, wax paper polishing agents, textile waterproofing agents and other products. It is a solvent for oil-soluble pigment. It is also a raw material for the production of more fatty acid esters and stearates such as methyl stearate, glyceryl stearate, calcium stearate, potassium stearate, lead stearate, etc.
Stearic acid is made from hydrogenated cottonseed oil, palm oil, etc. into tallow and mutton fat hydrolyzed in the presence of a decomposition agent (beneficid, benzene, naphthalene and other mixtures by sulfonation), and then produced by distillation, pressing (or without pressing), pickling and decolorization.