Stearic Acid
Stearic acid (/ˈstɪərɪk/ STEER-ik, /stiˈærɪk/ stee-ARR-ik) is a saturated fatty acid with an 18-carbon chain.The IUPAC name is octadecanoic acid. It is a soft waxy solid with the formula CH3(CH2)16CO2H.The triglyceride derived from three molecules of stearic acid is called stearin.Stearic acid is a prevalent fatty-acid in nature, found in many animal and vegetable fats, but is usually higher in animal fat than vegetable fat. It has a melting point of 69.4 °C and a pKa of 4.50.
Its name comes from the Greek word στέαρ “stéar“, which means tallow. The salts and esters of stearic acid are called stearates. As its ester, stearic acid is one of the most common saturated fatty acids found in nature and in the food supply, following palmitic acid. Dietary sources of stearic acid include meat, poultry, fish, eggs, dairy products, and foods prepared with fats; beef tallow, lard, butterfat, cocoa butter, and shea butter are rich fat sources of stearic acid.
Application
Mainly used in the production of detergents, soaps and cosmetics such as shampoos and shaving cream products.
| Chemical formula | C18H36O2 |
|---|---|
| Molar mass | 284.484 g·mol−1 |
| Appearance | White solid |
| Odor | Pungent, oily |
| Density | 0.9408 g/cm3 (20 °C) |
| Melting Point | 69.3 °C (156.7 °F; 342.4 K) |
| Boiling Point | 361 °C (682 °F; 634 K) |
| Solubility in water | 0.00018 g/100 g (0 °C) |
| Solubility | Soluble in alkyl acetates, alcohols, HCOOCH3, phenyls, CS2, CCl4[4] |
| Solubility in dichloromethane | 3.58 g/100 g (25 °C) |
| Solubility in hexane | 0.5 g/100 g (20 °C) |
| Solubility in ethanol | 1.09 g/100 mL (10 °C) |
| Solubility in acetone | 4.73 g/100 g |
| Solubility in chloroform | 15.54 g/100 g |
| Solubility in toluene | 13.61 g/100 g |
| Vapor Pressure | 0.01 kPa (158 °C) |
| Magnetic susceptibility (χ) | −220.8·10−6 cm3/mol |
| Thermal conductivity | 0.173 W/m·K (70 °C) |
| Refractive index (nD) | 1.4299 (80 °C) |
Reviews
There are no reviews yet.