octadecanoic acid（CAS番号：57-11-4）

Widely used as a low-temperature plastic plasticizer, stabilizer, surfactant, demolding agent, and rubber vulcanization promoter. For water hardness determination, it is also used as an activator and diffusant for acidification. Used in the preparation of soap, cosmetics, pharmaceuticals, and other organic chemicals. Used as an emulsifier for oil-based drilling fluids. Also used as a lubricant and wetting agent in rubber industry and textile industry. Lubricant; anti-caking agent; gum base; defoamer and other food additives (such as glycerol stearate, sorbitan stearate ester, sucrose ester, etc.) as raw materials. Used as a vulcanization promoter for natural rubber, synthetic rubber (except butyl rubber) and latex, and as raw materials for plastic plasticizers and stabilizers. Used in medicine to prepare ointments, suppositories, etc., and for the manufacture of cosmetics, candles, water repellents, and polishers. In the food industry, used as a lubricant, defoamer, and raw materials for food additives such as glyceryl stearate, sorbitan stearate ester, sucrose ester, etc. For water hardness determination. In turbidimetric methods for calcium, magnesium, and lithium. Solvent for determining relative molecular weight. Active agent for acidification. Commercial stearic acid is actually a mixture of 45% stearic acid and 55% palmitic acid, and contains a small amount of oleic acid, and has a slight fatty scent. Stearic acid is widely used in cosmetics, plastic plasticizers, demolding agents, stabilizers, surfactants, rubber vulcanization promoters, water repellents, polishing agents, metal soaps, metal mineral flotation agents, softeners, pharmaceuticals, and other organic chemicals. Stearic acid can also be used as a solvent for oil-soluble pigments, crayon gliding agent, wax paper glazing agent, emulsifier for glyceryl stearate, etc. Stearic acid is widely used in the production of polyvinyl chloride pipe materials, plates, profiles, films, and is a heat stabilizer for polyvinyl chloride with good lubricity and better light and heat stabilizing effects. In polyvinyl chloride pipe materials, stearic acid helps prevent "charring" during the production process, and as a heat stabilizer in polyvinyl chloride films, it can prevent color changes in finished films due to sun exposure. Stearic acid has become a functional aid for lubrication, plasticization, and stabilization in filler modification masterbatches. Stearic acid can effectively improve the inorganic powder encapsulation and activation effect, increase material flowability. When the proportion of inorganic powders in the material is very large and requires a high melt flow rate, appropriately increasing the content of stearic acid can significantly increase the melt flow rate of the material. However, the amount of stearic acid in filler modification masterbatches also has a limit value, generally controlled at about 1% of the total mass. Adding too much can lead to a decline in the quality performance of plastic products, and may also cause paste-like substances at the die lip position of plastic product production equipment, affecting production efficiency and product quality. The monovalent or polyvalent stearic acid esters can be used as cosmetics, non-ionic surfactants, plasticizers, etc. Its alkali metal salts are soluble in water and are one of the main components of soap. Other metal salts can be used as water repellents, lubricants, fungicides, paint additives, and polyvinyl chloride stabilizers.