Ethylene glycol dinitrate

Ethylene glycol dinitrate
Skeletal formula of ethylene glycol dinitrate
Ball-and-stick model of the ethylene glycol dinitrate molecule
Names
IUPAC name
1,2-dinitroxyethane
Other names
Ethylene glycol dinitrate, Glycol dinitrate, Ethylene dinitrate, Ethylene nitrate, 1,2-Bis(nitrooxy)ethane, Nitroglycol (NGc), 1,2-Ethanediol dinitrate, Dinitroglycol, EGDN, Ethane-1,2-diyl dinitrate
Identifiers
628-96-6 
ChemSpider 37281 Yes
Jmol-3D images Image
Image
PubChem 40818
Properties
C2H4N2O6
Molar mass 152.1 g/mol
Appearance Oily, colorless to light yellow liquid
Odor odorless[1]
Density 1.49 g/cm3
Melting point −22.0 °C (−7.6 °F; 251.2 K)
Boiling point Explodes at 114 °C (237 °F; 387 K)
5 g/l
Vapor pressure 0.05 mmHg (20°C)[1]
Explosive data
Shock sensitivity Medium
Friction sensitivity Medium
Detonation velocity 8300 m/s [2]
Hazards
Main hazards
R-phrases R2 R26/27/28 R33
S-phrases ((S1/2) S33 S35 S36/37 S45
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 0: Exposure under fire conditions would offer no hazard beyond that of ordinary combustible material. E.g., sodium chloride Reactivity code 4: Readily capable of detonation or explosive decomposition at normal temperatures and pressures. E.g., nitroglycerin Special hazards (white): no codeNFPA 704 four-colored diamond
1
0
4
Flash point 215 °C; 419 °F; 488 K [1]
US health exposure limits (NIOSH):
C 0.2 ppm (1 mg/m3) [skin][1]
ST 0.1 mg/m3 [skin][1]
75 mg/m3[1]
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Ethylene glycol dinitrate (EGDN,NGc), also known as nitroglycol, is a chemical compound a yellowish, oily explosive liquid obtained by nitrating ethylene glycol. It is similar to nitroglycerin in both manufacture and properties, though it is more volatile and less viscous.

History and production

Pure EGDN was first produced by L. Henry in 1870 by dropping a small amount of ethylene glycol into a mixture of nitric and sulfuric acids cooled to 0 °C. The previous year, August Kekulé had produced pure EGDN by the nitration of ethylene, but this was actually contaminated with beta-nitroethyl nitrate.[3][4]

Other investigators preparing NGc before publication in 1926 of Rinkenbach's work included: Champion (1871), Neff (1899) & Wieland & Sakellarios (1920), Dautriche, Hough & Oehme.

Rinkenbach prepared EGDN by nitrating purified glycol obtained by fractioning the commercial product under pressure of 40mm Hg, and at temp 120 deg. For this 20g of middle fraction of purified glycol was gradually added to mixture of 70g nitric acid and 130g sulfuric acid, maintaining the temp at 23 deg.The resulting 49g of crude product was washed with 300ml of water to obtain 39.6g of purified product. The low yield so obtained could be improved by maintaining a lower temperature and using a different nitrating acid mixture.

1) Direct Nitration of Glycol is carried out in exactly the same manner, with the same apparatus, and with the same mixed acids as nitration of glycerine. In the test nitration of anhydrous glycol (100g) with 625g of mixed acid HNO
3 40 & H
2SO
4 60% at 10-12 deg, the yield was 222g and it dropped to 218g when the temp was raised to 29-30 deg. When 500g of mixed acid HNO
3 50 & H
2SO
4 50% was used at 10-12 deg, the yield increased to 229g. In commercial nitration, the yields obtained from 100 kg anhydrous glycol and 625 kg of mixed acid containing HNO
3 41, H
2SO
4 58 & water 1% were 222.2 kg of NGc at nitrating temp of 10-12 deg and only 218.3 kg at 29-30 deg. This means 90.6% of theory, as compared to 93.6% with NG.

C2H4(OH)2 + 2 HNO3 → C2H4(ONO2)2 + 2 H2O

or through the reaction of ethylene oxide and dinitrogen pentoxide:

C2H4O + N2O5 → C2H4(ONO2)2

2) Direct Production of NGc from Gaseous Ethylene. 3) Preparation of NGc from Ethylene Oxide. 4) Preparation of NGc by method of Messing from ethylene through chlorohydrin & ethylene oxide. 5) Preparation of NGc by duPont method.

Properties

Physical properties

Ethylene glycol dinitrate is a colorless volatile liquid when in pure state, but is yellowish when impure.

Molar weight 152.07, N 18.42%, OB to CO2 0%, OB to CO +21%; colorless volatile liquid when in pure state; yellowish liquid in crude state; sp gr 1.488 at 20/4° or 1.480 at 25°; n_D 1.4452 at 25° or 1.4472 at 20°; freezing point -22.75° (versus +13.1° for NG); frozen point given in[5] is -22.3°; boiling point 199° at 760mm Hg (with decomposition).

Brisance by lead block compression (Hess crusher test) is 30.0 mm, versus 18.5 mm for NG and 16 mm for TNT. Brisance by sand test, determined in mixtures with 40% kieselguhr, gave for NGc mixtures slightly higher results then with those containing NG.

Chemical properties

When ethylene glycol dinitrate is rapidly heated to 215 °C, it explodes; this is preceded by partial decomposition similar to that of nitroglycerin. EGDN has a slightly higher brisance than nitroglycerin.

Ethylene glycol dinitrate reacts violently with potassium hydroxide, yielding ethylene glycol and potassium nitrate:

C2H2(ONO2)2 + 2 KOH → C2H2(OH)2 + 2 KNO3

Other

EGDN was used in manufacturing explosives to lower the freezing point of nitroglycerin, in order to produce dynamite for use in colder weather. Due to its volatility it was used as a detection taggant in some plastic explosives, e.g. Semtex, to allow more reliable explosive detection, until 1995 when it was replaced by dimethyldinitrobutane. It is considerably more stable than glyceryl trinitrate owing to the lack of secondary hydroxyl groups in the precursor polyol.

Like other organic nitrates, ethylene glycol dinitrate is a vasodilator.

See also

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 "NIOSH Pocket Guide to Chemical Hazards #0273". National Institute for Occupational Safety and Health (NIOSH).
  2. ↑ Meyer, M.; Köhler, J.; Homburg, A. (2007). Explosives (PDF) (6th ed.). WILEY-VCH. p. 227. ISBN 978-3-527-31656-4. Retrieved 2013-08-03.
  3. ↑ Rinkenbach, W. H. (1926). "The Properties of Glycol Dinitrate". Industrial and Engineering Chemistry 18 (11): 1195–1197. doi:10.1021/ie50203a027.
  4. ↑ Wieland, H.; Sakellarios, E. (1920). "Die Nitrierung des Äthylens". Berichte der Deutschen Chemischen Gesellschaft 53 (2): 201–210. doi:10.1002/cber.19200530211.
  5. ↑ Curme, G. O.; Johnston, F., ed. (1952). Glycols. American Chemical Society Monograph 114. Reinhold. pp. 65–7, 130–134, 312. OCLC 558186858.

External links