Glycerine
(glycerin, glycerol, or 1,2,3-propanetriol)
is the simplest trihedric alcohol. Pure
glycerine, with a specific gravity of 1.26,
is a colorless, odorless, sweet, viscous
liquid melting at 17.8 C boiling at 290
C. It decomposes at boiling point
and produce corrosive fumes of
acrolein. It is miscible in water and forms a solution in any proportion. It
is also soluble alcohol but only partially
soluble in common organic solvents such
as ether and ethyl acetate. It resists freezing.
It is hygroscopic, which favors as
a humectant to retain moisture in cosmetics.
It reacts violently with acetic anhydrides in the presence of a
catalyst. It is obtained as a byproduct when fats and oils are hydrolyzed to
yield fatty acids or soaps. Glycerol is
also commercially synthesized from propylene
(Dow Chemical). Glycerol can also
be obtained based on a proprietary fermentation
processing. Glycerol is widely used; as
a solvent, food additive, sweetening agent
and emollient and emulcent with magnesium
sulphate used in the treatment of septic
wounds and boils; in the manufacture of
alkyd resin, cellophane, ester gums, plasticizer,
dynamite, nitroglycerine, cosmetics, liquid
soap, perfume and toothpaste (good solubility
and taste give glycerine an edge on sorbitol
in toothpastes, which are estimated to make
up almost one-third of glycerine's market
in personal care products); as a component
of antifreeze mixtures; to keep fabrics
pliable, to preserve printing on cotton,
to keep frost from windshields; as a source
of nutrients for fermentation cultures in
the production of antibiotics; as a preservative
in some pharmaceutical and biological preparations
and in non-alcoholic extracts and tinctures.
It has many other applications.
PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL
STATE
Clear oily liquid
MELTING POINT
18
C
BOLING
POINT
290
(Decomposes)
SPECIFIC GRAVITY
1.26
SOLUBILITY
IN WATER
Miscible
pH
VAPOR DENSITY
3.17
AUTOIGNITION
370
C
NFPA
RATINGS
Health: 1 Flammability: 1 Reactivity: 0
REFRACTIVE
INDEX
FLASH
POINT
199
C
STABILITY
Stable
under ordinary conditions
APPLICATIONS
Drugs and personal care, toothpaste, foods and beverages, tobacco, polyether
polyols for urethanes, alkyd resins,
cellophane, explosives ,plasticizer, humectant and lubricant
uses