Epichlorohydrin

(±)-Epichlorohydrin[1]
IUPAC name	chloromethyloxirane
Other names	epichlorohydrin 1-chloro-2,3-epoxypropane γ-chloropropylene oxide glycidyl chloride
Identifiers
CAS number	106-89-8 Y
PubChem	7835
SMILES	C1C2(O1)C2Cl
ChemSpider ID	7547
Properties
Molecular formula	C3H5ClO
Molar mass	92.52 g/mol
Density	1.1812 g/cm3
Melting point	-25.6 °C
Boiling point	117.9 °C
Hazards
MSDS	External MSDS
EU classification	T
NFPA 704	3 3 2
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Epichlorohydrin is an organochlorine compound and an epoxide. This is a colorless liquid with a pungent, garlic-like odor, insoluble in water, but miscible with most polar organic solvents.^[2] Epichlorohydrin is a highly reactive compound and is used in the production of glycerol, plastics, epoxy glues and resins, and elastomers. In contact with water, epichlorohydrin hydrolyzes to 3-MCPD, a carcinogen found in food.

Production

Epichlorohydrin is manufactured from allyl chloride in two steps, beginning with the hydrochlorination using hypochlorous acid, which affords a mixture of two alcohols:^[3]

CH₂=CHCH₂Cl + HOCl → HOCH₂CHClCH₂Cl and, or ClCH₂CH(OH)CH₂Cl

In the second step, this mixture is treated with base to give the epoxide:

HOCH₂CHClCH₂Cl and, or ClCH₂CH(OH)CH₂Cl + NaOH → CH₂CHOCH₂Cl + NaCl + H₂O

In this way, more than 700,000 tons of epichlorohydrin are produced annually.^[4]

Applications

Glycerol and epoxy resins synthesis

Epichlorohydrin is mainly converted to glycerol:

CH₂CHOCH₂Cl + 2 H₂O → HOCH₂CH(OH)CH₂(OH) + HCl

It is also a building block in the manufacture of epoxy resins, for example by alkylation of bisphenol-A. It is a precursor to monomers for other resins and polymers.

Minor and niche applications

Epichlorohydrin is a versatile precursor in the synthesis of many organic compounds. For example, it is converted to glycidyl nitrate, an energetic binder used in explosive and propellant compositions.^[5] The epichlorohydrin is reacted with an alkali nitrate, such as sodium nitrate, producing glycidyl nitrate and alkali chloride. It used as a solvent for cellulose, resins and paints and it has found use as an insect fumigant.^{[citation needed]}

Epichlorohydrin is used in paper reinforcement (used for instance in the food industry to manufacture tea bags, coffee filters, and sausage/salami casings) and water purification.^[6]

Safety

Epichlorohydrin is irritating and moderately toxic as well as carcinogenic.^[2]

See also

• Epoxy resins

References

1. ^ Merck Index, 12th Edition, 3648.
2. ^ ^{a b} EPA consumer factsheet
3. ^ Guenter Sienel, Robert Rieth, Kenneth T. Rowbottom "Epoxides" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.
4. ^ Ludger Krähling, Jürgen Krey, Gerald Jakobson, Johann Grolig, Leopold Miksche “Allyl compounds” in Ullmann's Encyclopedia of Industrial Chemistry Wiley-VCH, Weinheim, 2005. Published online: 15 June, 2000.
5. ^ Gould, R.F. Advanced Propellant Chemistry, ACS Chemistry Series 54, 1966
6. ^ http://www.chemicalsubstanceschimiques.gc.ca/challenge-defi/batch-lot-2/106-89-8_e.html