Glycol: any of a class of organic chemicals characterized by having separate two
hydroxyl (-OH) groups, contribute to high water solubility, hygroscopicity and
reactivity with many organic compounds, on usually linear and aliphatic carbon
chain. The general formula is CnH2n(OH)2 or (CH2)n(OH)2. The broadened names
include diols, dihydric alcohols, and dihydroxy alcohols. Ethylene glycol,
HOCH2CH2OH, is the simplest member of the glycol family. Mono-, di- and
triethylene glycols are the first three members of a homologous series of
dihydroxy alcohols. Propylene glycol prepared by hydrolysis of propylene oxide
and widely used as an ingredient of antifreeze and humectant in cosmetics is
1,2-propanediol indicating the two hydroxyl group position at 1,2, while
trimethylene glycol is 1,3-propanediol with two hydroxyl group on the primary
carbon atoms. 1,3-propanediol is called beta-propylene
glycol. Trimethylene glycol is a clear, oily liquid; soluble in water;
soluble in oxygenated solvents and completely soluble
in alcohol; melting point -27 C; boiling point
210 C.
Trimethylene glycol
has similar applications to Propylene glycol. It is
can be used as a comonomer of unsaturated polyester
resins, alkyd resins, polyester foams, polyester-based
plasticizers, and as chain extender for polyurethane.
It is a useful chemical intermediate which have two hydroxyl group on the primary
carbon atoms and one alpha-carbon atom. 1,3-propanediol, or a derivative thereof,
is used for the
synthesis of lubricants, plasticizers, adhesives, photographic materials,
pharmaceuticals, insect
repellent, fragrances,
antioxidant compound,
antistatic agents, fabric
softeners, and vitamin H.
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