Stearin

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Stearin[1]
Skeletal formula of stearin
Space-filling model of the tristearin molecule
Powder of stearin
Names
Systematic IUPAC name
Propane-1,2,3-triyl tri(octadecanoate)
Other names
Tristearin; Trioctadecanoin; Glycerol tristearate; Glyceryl tristearate
Identifiers
3D model (
JSmol
)
ChEBI
ChemSpider
ECHA InfoCard
 100.008.271 Edit this at Wikidata
KEGG
UNII
  • InChI=1S/C57H110O6/c1-4-7-10-13-16-19-22-25-28-31-34-37-40-43-46-49-55(58)61-52-54(63-57(60)51-48-45-42-39-36-33-30-27-24-21-18-15-12-9-6-3)53-62-56(59)50-47-44-41-38-35-32-29-26-23-20-17-14-11-8-5-2/h54H,4-53H2,1-3H3 ☒N
    Key: DCXXMTOCNZCJGO-UHFFFAOYSA-N ☒N
  • InChI=1S/C57H110O6/c1-4-7-10-13-16-19-22-25-28-31-34-37-40-43-46-49-55(58)61-52-54(63-57(60)51-48-45-42-39-36-33-30-27-24-21-18-15-12-9-6-3)53-62-56(59)50-47-44-41-38-35-32-29-26-23-20-17-14-11-8-5-2/h54H,4-53H2,1-3H3
    Key: DCXXMTOCNZCJGO-UHFFFAOYSA-N
  • CCCCCCCCCCCCCCCCCC(=O)OCC(COC(=O)CCCCCCCCCCCCCCCCC)OC(=O)CCCCCCCCCCCCCCCCC
Properties
C57H110O6
Molar mass 891.501 g·mol−1
Appearance White powder
Odor Odorless
Density 0.862 g/cm3 (80 °C)
0.8559 g/cm3 (90 °C)[2]
Melting point 54–72.5 °C (129.2–162.5 °F; 327.1–345.6 K)[3]
Insoluble
Solubility Slightly soluble in C6H6, CCl4
Soluble in acetone, CHCl3
Insoluble in EtOH[2]
1.4395 (80 °C)[2]
Structure
Triclinic (β-form)[4]
P1 (β-form)[4]
a = 12.0053 Å, b = 51.902 Å, c = 5.445 Å (β-form)[4]
α = 73.752°, β = 100.256°, γ = 117.691°
Thermochemistry
1342.8 J/mol·K (β-form, 272.1 K)
1969.4 J/mol·K (346.5 K)[3][5]
1534.7 J/mol·K (liquid)[5]
Std enthalpy of
formation
(ΔfH⦵298)
 −2344 kJ/mol[5]
Std enthalpy of
combustion
(ΔcH⦵298)
 35806.7 kJ/mol[5]
Hazards
NFPA 704 (fire diamond)
[6]
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
1
0
Flash point ≥ 300 °C (572 °F; 573 K) closed cup[6]
Lethal dose or concentration (LD, LC):
2000 mg/kg (rats, oral)[6]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

Stearin

polymorphs. For stearin, these melt at 54 (α-form), 65, and 72.5 °C (β-form).[3]

Note that stearin is also used to mean the solid component of an oil or fat that can be separated into components that melt at higher (the stearin) and lower (the olein) temperatures. This is the usage meant in an example such as palm stearin.

Occurrence

Stearin is obtained from animal

interesterification, again exploiting its higher melting point which allows the higher melting tristearin to be removed from the equilibrated mixture. Stearin is a side product obtained during the extraction of cod liver oil
removed during the chilling process at temperatures below −5 °C.

Uses

Stearin is used as a hardening agent in the manufacture of

glycerin and sodium stearate
, the main ingredient in most soap:

C3H5(C18H35O2)3 + 3 NaOH → C3H5(OH)3 + 3 C18H35OONa

Stearin is also added to aluminium flakes to help in the grinding process in making dark aluminium powder.[clarification needed]

See also

References

  1. ^ Merck Index, 11th Edition, 9669.
  2. ^
    ISBN 978-1-4200-9084-0
    .
  3. ^
    S2CID 101805872
    .
  4. ^
    PMID 11373397
    .
  5. ^ a b c d Tristearin in Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD) (retrieved 2014-06-19)
  6. ^ a b c "MSDS of Stearin Wax" (PDF). www.swna.us. Sasol Wax North America Corp. Archived from the original (PDF) on 2016-03-04. Retrieved 2014-06-19.
  7. ISBN 978-3527306732
    .
  8. S2CID 97117097
    .
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