Sodium stearate

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Sodium stearate
Sodium stearate.png
Identifiers
CAS number 822-16-2 YesY
PubChem 2724691
ChemSpider 12639 YesY
UNII QU7E2XA9TG YesY
EC number 212-490-5
Jmol-3D images Image 1
Properties
Molecular formula C18H35NaO2
Molar mass 306.46 g mol−1
Appearance Yellow/white solid
Odor slight, tallow-like odo
Density 1.02 g/cm3
Melting point 245 to 255 °C (473 to 491 °F; 518 to 528 K)
Solubility in water soluble
Solubility slightly soluble in ethanediol
Hazards
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 176 °C (349 °F; 449 K)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Sodium stearate is the sodium salt of stearic acid. This white solid is the most common soap. It is found in many types of solid deodorants, rubbers, latex paints, and inks. It is also a component of some food additives and food flavorings.[1]

Use[edit]

Characteristic of soaps, sodium stearate has both hydrophilic and hydrophobic parts, the carboxylate and the long hydrocarbon chain, respectively. These two chemically different components induce the formation of micelles, which present the hydrophilic heads outwards and their hydrophobic (hydrocarbon) tails inwards, providing a lipophilic environment for hydrophobic compounds.The tail part dissolves the grease (or) dirt and forms the micelle. It is also used in the pharmaceutical industry as a surfactant to aid the solubility of hydrophobic compounds in the production of various mouth foams.

Production[edit]

Sodium stearate is produced as a major component of soap upon saponification of oils and fats. The percentage of the sodium stearate depends on the ingredient fats. Tallow is especially high in stearic acid content (as the triglyceride), whereas most fats only contain a few percent. The idealized equation for the formation of sodium stearate from stearin (the triglyceride of stearic acid) follows:

(C18H35O2)3C3H5 + 3 NaOH → C3H5(OH)3 + 3 C17H35CO2Na

Purified sodium stearate can be made by neutralizing stearic acid with sodium hydroxide.

References[edit]

  1. ^ Klaus Schumann, Kurt Siekmann, "Soaps" in Ullmann's Encyclopedia of Industrial Chemistry, 2005 Wiley-VCH, Weinheim. doi:10.1002/14356007.a24_247

External links[edit]