Ethylene glycol dinitrate

Ethylene glycol dinitrate
Identifiers
CAS number 628-96-6
PubChem 40818
ChemSpider 37281 Y
Jmol-3D images Image 1
Image 2
Properties
Molecular formula C2H4N2O6
Molar mass 152.1 g/mol
Appearance Oily, odorless, colorless to light yellow liquid
Density 1.49 g/cm3
Melting point

-22.0 °C

Boiling point

Explodes at 114 °C

Solubility in water 5 g/l
Hazards
R-phrases R2 R26/27/28 R33
S-phrases ((S1/2) S33 S35 S36/37 S45
Main hazards
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
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.

Contents

History and production

L. Henry was the first who prepared EGDN in a pure state (1870) by dropping small portions of glycole into mixture of nitric and sulfuric acids cooled to 0 deg. A. Kekulé previously (1869) nitrated ethylene and obtaned an unstable material, which was presumed to be Glycole Nitrite-Nitrate, but which in 1920 was shown by Wieland & Sakellarios to be a mixture of EGDN and nitric ester \beta-Nitroethyl Alcohol.[1] 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.

The book of Naoum are describing several methods of laboratory and industrial preparation of EGDN, such as: 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 HNO3 40 & H2SO4 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 HNO3 50 & H2SO4 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 HNO3 41, H2SO4 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. 2) Direct Production of NGc from Gaseous Ethylene. This method was introduced after World War I by the Chemische Fabrik Kalk, GmbH in Köln-Kalk by Dr H. Oehme and later patented in USA. 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

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° (vs +13.1° for NG); frozen point given in [2] is -22.3°; boiling point 199° at 760mm Hg (with decomposition).

Wieland & Sakellarios ([3] quote [1] at p1499) found EGDN to boil at 105.5° under a pressure of 19mm Hg, but when quickly heated under atmosphere pressure it exploded at 215°. This was preceded by partial decomposition analogous to that found in case of NG.

Brisance by lead block compression (Hess crusher test) --- 30.0mm, vs 18.5mm for NG and 16mm 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. On heating with solutions of alkalies, gradual solution with saponification, similar to NG, takes place. With KOH, NGc reacts violently with formation of K nitrate and glycolate. Chemical test for purity is conducted with Nitrometer Method, originated by Lange but modified by duPont Co. N content of NGc should be about 18.42%, vs 18.50 for NG. Critical temperature -- 114-116 degrees.

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 did serve 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. ^ a b Wm.H. Rinkenbach, IEC 18, pp.1195–1200 (1926)
  2. ^ Curme, Johnston (1952), 65-7, pp.130-34,312
  3. ^ H.Wieland, E.Sakellarios, Ber 53B, p203 (1920)

External links