Stearin

Stearin

Names
IUPAC name 1,3-Di(octadecanoyloxy)propan-2-yl octadecanoate
Other names Tristearin; Trioctadecanoin; Glycerol tristearate; Glyceryl tristearate
Identifiers
CAS Number	555-43-1 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:45956 N
ChemSpider	10673 N
ECHA InfoCard	100.008.271
KEGG	D10637 Y
PubChem CID	11146
InChI 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
SMILES CCCCCCCCCCCCCCCCCC(=O)OCC(COC(=O)CCCCCCCCCCCCCCCCC)OC(=O)CCCCCCCCCCCCCCCCC
Properties
Chemical formula	C57H110O6
Molar mass	891.50 g·mol−1
Appearance	White powder
Odor	Odorless
Density	0.862 g/cm3 (80 °C) 0.8559 g/cm3 (90 °C)
Melting point	54–72.5 °C (129.2–162.5 °F; 327.1–345.6 K)
Solubility in water	Insoluble
Solubility	Slightly soluble in C6H6, CCl4 Soluble in acetone, CHCl3 Insoluble in EtOH
Refractive index (nD)	1.4395 (80 °C)
Structure
Crystal structure	Triclinic (β-form)
Space group	P1 (β-form)
Lattice constant	a = 12.0053 Å, b = 51.902 Å, c = 5.445 Å (β-form) α = 73.752°, β = 100.256°, γ = 117.691°
Thermochemistry
Specific heat capacity (C)	1342.8 J/mol·K (β-form, 272.1 K) 1969.4 J/mol·K (346.5 K)
Std molar entropy (So298)	1534.7 J/mol·K (liquid)
Std enthalpy of formation (ΔfHo298)	−2344 kJ/mol
Std enthalpy of combustion (ΔcHo298)	35806.7 kJ/mol
Hazards
NFPA 704	1 1 0
Flash point	≥ 300 °C (572 °F; 573 K) closed cup
Lethal dose or concentration (LD, LC):
LD50 (median dose)	2000 mg/kg (rats, oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Stearin /ˈstɪərᵻn/, or tristearin, or glyceryl tristearate is a triglyceride derived from three units of stearic acid. Most triglycerides are derived from at least two and more commonly three different fatty acids. Like other triglycerides, stearin can crystallise in three polymorphs. For stearin, these melt at 54 (α-form), 65, and 72.5 °C (β-form).

Stearin is obtained from animal fats created as a byproduct of processing beef. It can also be found in tropical plants such as palm. It can be partially purified by "dry fractionation" by pressing tallow or other fatty mixtures, leading to separation of the higher melting stearin-rich material from the liquid, which is typically enriched in fats derived from oleic acid. It can be obtained by "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.

It is used as a hardening agent in the manufacture of candles and soap. In the manufacture of soap, stearin is mixed with a sodium hydroxide solution in water. The following reaction gives glycerin and sodium stearate, the main ingredient in most soap:

Stearin is also used in conjunction with aluminium flakes to help in the grinding process in making dark aluminium powder.