Ethylene glycol dinitrate, abbreviated EGDN and NGC, also known as Nitroglycol, is a colorless, oily, explosive liquid obtained by nitrating

ethylene glycol Ethylene glycol ( IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula . It is mainly used for two purposes: as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odo ...

. It is similar to

nitroglycerine Nitroglycerin (NG) (alternative spelling nitroglycerine), also known as trinitroglycerol (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless or pale yellow, oily, explosive liquid most commonly produced by ...

in both manufacture and properties, though it is more volatile and less

viscous Viscosity is a measure of a fluid's rate-dependent resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for example, syrup h ...

. Unlike nitroglycerine, the chemical has a perfect

oxygen balance Oxygen balance (OB, OB%, or Ω) is an expression that is used to indicate the degree to which an explosive can be oxidized, to determine whether the molecules of explosive substance or mixture contains enough oxygen to fully oxidize the other atom ...

, meaning that its ideal exothermic decomposition would completely convert it to low energy

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

water Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...

, and nitrogen gas, with no excess unreacted substances, without needing to react with anything else.

History and production

Pure EGDN was first produced by the Belgian chemist Louis Henry (1834–1913) in 1870 by dropping a small amount of ethylene glycol into a mixture of nitric and

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...

s cooled to 0 °C. The previous year,

August Kekulé Friedrich August Kekulé, later Friedrich August Kekule von Stradonitz ( , ; 7 September 1829 – 13 July 1896), was a German organic chemist. From the 1850s until his death, Kekulé was one of the most prominent chemists in Europe, especially ...

had produced EGDN by the nitration of

ethylene Ethylene (IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon–carbon bond, carbon–carbon doub ...

, but this was actually contaminated with beta-nitroethyl nitrate. Other investigators preparing NGC before publication in 1926 of Rinkenbach's work included: Champion (1871), Neff (1899) & Wieland & Sakellarios (1920), Dautriche, Hough & Oehme. The American chemist William Henry Rinkenbach (1894–1965) prepared EGDN by nitrating purified glycol obtained by fractioning the commercial product under pressure of 40mm Hg, and at a temperature of 120°. For this 20g of middle fraction of purified glycol was gradually added to mixture of 70g nitric acid and 130g sulfuric acid, maintaining the temperature at 23°. 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 40% & 60% at 10-12°, the yield was 222g and it dropped to 218g when the temp was raised to 29-30°. When 500g of mixed acid 50% & 50% was used at 10-12°, the yield increased to 229g. In commercial nitration, the yields obtained from 100 kg anhydrous glycol and 625 kg of mixed acid containing 41%, 58% & water 1% were 222.2 kg of NGc at nitrating temp of 10-12° and only 218.3 kg at 29-30°. 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 Ethylene oxide is an organic compound with the chemical formula, formula . It is a cyclic ether and the simplest epoxide: a three-membered ring (chemistry), ring consisting of one oxygen atom and two carbon atoms. Ethylene oxide is a colorless ...

and

dinitrogen pentoxide Dinitrogen pentoxide (also known as nitrogen pentoxide or nitric anhydride) is the chemical compound with the formula . It is one of the binary nitrogen oxides, a family of compounds that contain only nitrogen and oxygen. It exists as colourless c ...

: :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 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 (misleading, needs to give exact density and mass of explosive (25 or 50 g). Brisance by sand test, determined in mixtures with 40%

kieselguhr Diatomaceous earth ( ), also known as diatomite ( ), celite, or kieselguhr, is a naturally occurring, soft, siliceous rock, siliceous sedimentary rock that can be crumbled into a fine white to off-white powder. It has a particle size ranging fr ...

, 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 Brisance (; ) is the shattering capability of a high explosive, determined mainly by its detonation pressure. Application Brisance is of practical importance in explosives engineering for determining the effectiveness of an explosion in blasti ...

than nitroglycerin. Ethylene glycol dinitrate reacts violently with

potassium hydroxide Potassium hydroxide is an inorganic compound with the formula K OH, and is commonly called caustic potash. Along with sodium hydroxide (NaOH), KOH is a prototypical strong base. It has many industrial and niche applications, most of which utili ...

, yielding ethylene glycol and

potassium nitrate Potassium nitrate is a chemical compound with a sharp, salty, bitter taste and the chemical formula . It is a potassium salt of nitric acid. This salt consists of potassium cations and nitrate anions , and is therefore an alkali metal nit ...

: :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 Dynamite is an explosive made of nitroglycerin, sorbents (such as powdered shells or clay), and Stabilizer (chemistry), stabilizers. It was invented by the Swedish people, Swedish chemist and engineer Alfred Nobel in Geesthacht, Northern German ...

for use in colder weather. Due to its volatility it was used as a detection taggant in some

plastic explosive Plastic explosive is a soft and hand-moldable solid form of explosive material. Within the field of explosives engineering, plastic explosives are also known as putty explosives or blastics. Plastic explosives are especially suited for explos ...

s, e.g.

Semtex Semtex is a general-purpose plastic explosive containing RDX and PETN. It is used in commercial blasting, demolition, and in certain military applications. Semtex was developed and manufactured in Czechoslovakia, originally under the name B 1 a ...

, to allow more reliable

explosive detection Explosive detection is a non-destructive inspection process to determine whether a container contains explosive material. Explosive detection is commonly used at airports, ports and for border control. Detection tools Colorimetrics & automated ...

, until 1995 when it was replaced by dimethyldinitrobutane. It is considerably more stable than

glyceryl trinitrate Nitroglycerin (NG) (alternative spelling nitroglycerine), also known as trinitroglycerol (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless or pale yellow, oily, explosive liquid most commonly produced by ...

owing to the lack of secondary hydroxyl groups in the precursor

polyol In organic chemistry, a polyol is an organic compound containing multiple hydroxyl groups (). The term "polyol" can have slightly different meanings depending on whether it is used in food science or polymer chemistry. Polyols containing two, th ...

. Like other organic nitrates, ethylene glycol dinitrate is a

vasodilator Vasodilation, also known as vasorelaxation, is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. Blood vessel wal ...

References

External links

WebBook page for ethylene glycol dinitrate
{{DEFAULTSORT:Ethylene Glycol Dinitrate Nitrate esters Antianginals Explosive chemicals Liquid explosives Explosive detection Sugar alcohol explosives Glycol esters