Trinitrotoluene
Trinitrotoluene is an
explosive. Its empirical formula is C7H5N3O6.
The name for TNT is, in accordance with the nomenclature of the
IUPAC,
2-methyl-1,3,5-trinitrobenzene. In this article the more common designation
trinitrotoluene is used.
TNT was first synthesised by Joseph Wilbrand in 1863, and the first large-scale production began in
Germany in 1891.
The explosive yield of TNT is considered the standard measure of strength of
bombs and other
explosives .
Encyclopedia
| Structure Formula |
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| General Information |
|---|
| Name | Trinitrotoluene |
| Other Names | 2-Methyl-1,3,5-trinitrobenzene
2,4,6-Trinitrotoluene
TNT
Trotyl |
| Empirical formula | C7H5N3O6 |
| CAS Number | 118-96-7 |
| PubChem | |
| Short description | Pale, yellow, needle-shaped crystals |
| Characteristics |
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| Molar mass | 227.13 g/mol |
| Molecular weight | 227.131 g/mol |
| Phase | solid |
| Shock sensitivity | Insensitive |
| Friction sensitivity | Insensitive |
| Density | 1.654 g/cm³ |
| Explosive velocity | 6,900 m/s |
| RE factor | 1.00 |
| Melting Point | 80.35 °C |
| Boiling Point | 295 °C |
| Vapor pressure | 0.057 hPa |
| Solubility | Well in ether, acetone, benzene, badly in water |
| Safety References |
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| Hazard symbol |
> | | R/S Statements |
R: 2-23/24/25-33-51/53
S: 35-45-61 |
| TLV | 0.1 mg/m³ |
| The widely accepted SI Units have been used here. Unless otherwise indicated, assume the data is measured under Standard conditions for temperature and pressure. |
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Trinitrotoluene is an
explosive. Its empirical formula is C
7H
5N
3O
6.
The name for TNT is, in accordance with the nomenclature of the
IUPAC,
2-methyl-1,3,5-trinitrobenzene. In this article the more common designation
trinitrotoluene is used.
TNT was first synthesised by Joseph Wilbrand in 1863, and the first large-scale production began in
Germany in 1891.
The explosive yield of TNT is considered the standard measure of strength of
bombs and other
explosives .
Characteristics
Trinitrotoluene is in the form of pale yellow, needle-shaped crystals and can be distilled in a vacuum. It is difficult to dissolve TNT in water; it is more soluble in
ether,
acetone,
benzene and
pyridine. With its low melting point of 80.35 °C, TNT can be melted in water vapour and poured into forms. TNT is poisonous and skin contact can cause allergic reactions, causing the skin to turn a bright yellow-orange color.
- Water solubility: 130 mg/L at 20 °C
- Steam pressure at 20 °C: 1.5 -6 mbar
- Detonation speed: 6700-7000 m/s 6900 m/s
- Lead block test: 300 ml/10 g
- Sensitivity to impact: 15 Nm
- Friction sensitivity: to 353 N no reaction
Toxicity
Some military testing grounds are contaminated with TNT. Wastewater from munitions programs including contamination of surface and
subsurface waters may be colored pink as the result of TNT and RDX contamination. Such contamination, called pinkwater, may be difficult and expensive to remedy.
TNT is quite
toxic. It can also be absorbed through the skin, and will cause irritation and bright yellow staining. During the
First World War, munition workers who handled the chemical found that their
skin turned bright yellow, which led to the nickname "canary girls" or simply "canaries" to describe such workers. TNT would also eventually make ginger hair turn green. A 1916 British Government inquiry on female workers at the
Royal Arsenal, Woolwich found that 37% had severe pains due to loss of appetite, nausea and constipation, 25% suffered from dermatitis, and 34% experienced changes in
menstruation. Before respirators and protective grease applied to the skin were introduced, about 100 workers died from the disease.
People exposed to trinitrotoluene over a prolonged period tend to experience anemia and abnormal
liver functions.
Blood and
liver effects,
spleen enlargement and other harmful effects on the
immune system have also been found in animals that ingested or breathed trinitrotoluene. There is evidence that TNT adversely affects
male fertility, and TNT is listed as a possible human carcinogen. Consumption of TNT produces black urine.
History
TNT was first made in 1863 by a
German chemist Joseph Wilbrand, but its potential was not seen for several years, mainly because it was so hard to detonate and because it was less powerful than other explosives. Among its advantages, however, is its ability to be safely melted using
steam or hot
water, allowing it to be poured molten into shell cases. It is also so insensitive that, for example, in 1910 it was exempted from the UK's Explosives Act 1875, i.e. not actually being considered an explosive for the purposes of manufacture and storage.
The
German armed forces adopted it as an
artillery shell filling in 1902. A particular advantage that it gave the
German Navy in the
First World War was being able to detonate their TNT-filled armour-piercing shells after they had penetrated the armour of British capital ships, whereas the British
lyddite-filled shells tended to explode as soon as they struck the German armour, and thus expended much of their energy outside the ship. The British gradually started using it as replacement for lyddite in 1907.
Because of the insatiable demand for explosives during the Second World War, TNT was frequently mixed with 40%-80%
ammonium nitrate, producing an explosive called amatol. Although nearly as powerful as TNT amatol suffered from the slight disadvantage of being hygroscopic . Another variation called
minol, consisting of amatol mixed with about 20%
aluminum powder, was used by the British in mines and depth charges. Although blocks of pure TNT are available in various sizes eg 250g, 500g and 1 kg etc., it is more commonly encountered in explosive blends which comprise a variable percentage of TNT plus other ingredients, e.g. Torpex, Tritonal, Pentolite and Composition B.
Preparation
The synthesis is done in a stepwise procedure. First
toluene is nitrated with a mixture of
sulfuric and
nitric acid. Even lower-concentrated acid mixtures are capable of doing the first and second introduction of a nitrogroup. The nitrogroups decrease the reactivity of the toluene drastically, because they are electron-withdrawing groups. After separation the mono- and dinitrotoluene is fully nitrated with a mixture of nitric acid and oleum . This mixture is far more reactive and is capable of introducing the last nitrogroup. The waste acid from this process is used for the first step of the reaction in industrial synthesis.
See also
- dynamite
- hexanitrobenzene
- megaton
- tetryl
External links
