Sodium Stearate
Synonyms
Stearic acid, sodium salt
Octadecanoic acid, sodium salt
Sodium octadecanoate;
Category
Anionic Surfactant
> Carboxylate
>> Chain Carboxylate
>>> Alkyl Carboxylate
>>>> Linear Alkyl Carboxylate
Chemical Numbering System
CAS: 822-16-2
EINECS: 212-490-5
Molecular Formula & Molecular Weight
Molecular Formula: C18H35NaO2; C18H36O2.Na
Molecular Weight: 306.46
Structure
Properties
Appearance (1), white powder.
Solubility slightly soluble in water, slightly soluble in ethanol. soluble in hot water, after cooling, substantially form transparent gel.
Stability stable.
Risk Solid form: flammable material; irritation, irritation to skin, eye, respiratory system. Harmful products of combustion are CO, CO2 and so on. Contact with strong oxidants, can cause to burn.
GHS label: 
Animal Toxicity
Table 1 Animal toxicity values
|
dog intravenous LDLo |
10mg/kg[1] |
Ecology may be hazardous to environment. Water body should be given special attention.
Biodegradability biodegradable.
Characteristics excellent lubricating, cleansing, emulsifying, dispersing, foaming, solubilizing abilities. Nonresistant to hard water. Typical ingredient in soap(sodium soap).
Synthesis
Heat stearic acid to melt, add sodium hydroxide solution, and neutralize, obtain.
Quality Standards & Test Methods
1, Physical and chemical indexes
|
Item |
Physical and chemical indexes |
|
Solid |
|
|
Actives, %, ≥ |
98.0 |
|
Free acid, % , ≤ |
0.5 |
|
Moisture, %, ≤ |
1.5 |
Test Methods
(1), Actives
GB/T 13173 Surface active agents -- Detergents -- Testing methods
GB/T 5173 Surface active agents and detergents -- Determination of anionic-active matter by direct two-phase titration procedure
ISO 2271 Surface active agents -- Detergents -- Determination of anionic-active matter by manual or mechanical direct two-phase titration procedure
(2), Free acid
(3), Moisture
GB/T 13173 Surface active agents -- Detergents -- Testing methods
2, Hazardous substances indexes
|
Item |
Hazardous substances indexes |
|
Solid |
|
|
Heavy metals (as Pb), mg/kg, ≤ |
20 |
|
As, mg/kg, ≤ |
3 |
Test Methods
(1), Heavy metals (as Pb)
Safety and Technical Standards for Cosmetics (2015 Edition)
GB/T 30799 The test method of food detergents -- Determination of heavy metals
(2), As
Safety and Technical Standards for Cosmetics (2015 Edition)
GB/T 30797 The test method of food detergents -- Determination of total arsenic
3, Further explanation
(a), On physical and chemical indexes: firstly, shall be indicated carbon atom distribution; secondly, shall be indicated average molecular weight.
(b), Used in cosmetics, should be test for harmful substances; or furtherly test for microorganisms.
Major Uses
1, Typical applications
Use as lubricant.
Use as cleansing agent.
Use as emulsifying agent, dispersing agent.
2, Household detergents
Use as cleansing agent.
3, Personal care products
Cleansing agent, emulsifying agent, viscosity controlling agent in personal care products.
Can make the paste stable and white.
4, Machinery industry
Lubricant in metal processing, machinery.
5, Rubber industry
Vulcanization active agent, plasticizer, softening agent, emulsifying agent, release agent in synthesis and processing of rubber.
6, Plastics
Use as heat stabilizer, lubricant. For example: processing and manufacturing of PE.
7, Pets
Use as cleansing agent, emulsifying agent.
Manufacturers
References
[1]: ChemIDplus. 822-16-2, Sodium stearate
Update: 20131102(1); 20171215(2);