Tetryl

2,4,6-Trinitrophenylmethylnitramine commonly referred to as tetryl (C7H5N5O8) is an explosive compound used to make detonators and explosive booster charges.

Tetryl
Names
Preferred IUPAC name
N-Methyl-N-(2,4,6-trinitrophenyl)nitramide
Other names
  • Nitramine (incorrect)
  • Tetralite
  • Tetril
  • N-Methyl-N,2,4,6-tetranitroaniline
  • N-Methyl-N,2,4,6-tetranitrophenyl-1-amine
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.006.848
UNII
UN number 0208
Properties
C7H5N5O8
Molar mass 287.144 g·mol−1
Appearance Yellow crystalline solid
Odor Odorless
Density 1.73 g/cm3
Melting point 129.5 °C (265.1 °F; 402.6 K)
Boiling point 187 °C (369 °F; 460 K) decomposes
Virtually insoluble
Vapor pressure <1 mmHg (20°C)[1]
Explosive data
Shock sensitivity Sensitive
Friction sensitivity Sensitive
Detonation velocity 7,570 m/s (24,836 f/s)
RE factor 1.25
Hazards
Lethal dose or concentration (LD, LC):
5000 mg/kg (dog, subcutaneous)[2]
NIOSH (US health exposure limits):
PEL (Permissible)
 TWA 1.5 mg/m3 [skin][1]
REL (Recommended)
 TWA 1.5 mg/m3 [skin][1]
IDLH (Immediate danger)
 750 mg/m3[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y verify (what is YN ?)
Infobox references

Tetryl is a nitramine booster explosive, though its use has been largely superseded by RDX. Tetryl is a sensitive secondary high explosive used as a booster, a small charge placed next to the detonator in order to propagate detonation into the main explosive charge.

Chemical properties

Tetryl is a yellow crystalline solid powder material, practically insoluble in water but soluble in acetone, benzene and other solvents. When tetryl is heated, it first melts, then decomposes and explodes. It burns readily and is more easily detonated than ammonium picrate[3] or TNT, being about as sensitive as picric acid. It is detonated by friction, shock, or spark. It remains stable at all temperatures which may be encountered in storage. It is generally used in the form of pressed pellets, and has been approved as the standard bursting charge for small-caliber projectiles, since it gives much better fragmentation than TNT. It has an explosive velocity of 23,600–23,900 feet per second (7200–7300 m/s). Tetryl is the basis for the service tetryl blasting caps necessary for positive detonation of TNT. A mixture of mercury fulminate and potassium chlorate is included in the cap to ensure detonation of tetryl.[3]

Environmental fate

The most toxic ordnance compounds, tetryl and 1,3,5-TNB, are also the most degradable. Therefore, these chemicals are expected to be short-lived in nature, and environmental impacts would not be expected in areas that are not currently subject to chronic inputs of these chemicals. Tetryl decomposes rapidly in methanol/water solutions, as well as with heat. All aqueous samples expected to contain tetryl should be diluted with acetonitrile prior to filtration and acidified to pH < 3. All samples expected to contain tetryl should not be exposed to temperatures above room temperature. In addition, degradation products of tetryl appear as a shoulder on the 2,4,6-TNT peak. Peak heights rather than peak areas should be used when tetryl is present in concentrations that are significant relative to the concentration of 2,4,6-TNT.[3]

History
Cross-sectional view of Oerlikon 20 mm cannon shells (dating from circa 1945) showing color code for tetryl filling

Tetryl was used mainly during World Wars I and II and later conflicts. Tetryl is usually used on its own, though can sometimes be found in compositions such as tetrytol. Tetryl is no longer manufactured or used in the United States, but can still be found in legacy munitions such as the M14 anti-personnel landmine.[4]

Production

Tetryl is produced by simply slowly mixing dimethylaniline with concentrated nitric acid in the presence of sulfuric acid.

Health concerns

Although tetryl is among the most toxic explosive compounds, it is very short-lived. This combined with the fact that the health impacts of this compound are largely unstudied, not much is known about any health problems that this compound may cause.

Epidemiological data shows that tetryl has most effect on the skin, acting as a strong irritant.[5] Symptoms of skin sensitization such as dermatitis, itch, erythema, etc. may occur.[6] Tetryl can also affect mucous membranes, the upper respiratory tract, and possibly the liver.

See also

References
  1. NIOSH Pocket Guide to Chemical Hazards. "#0607". National Institute for Occupational Safety and Health (NIOSH).
  2. "Tetryl". Immediately Dangerous to Life and Health Concentrations (IDLH). National Institute for Occupational Safety and Health (NIOSH).
  3. http://www.globalsecurity.org/military/systems/munitions/explosives-booster.htm
  4. “A Military Guide to Terrorism in the 21st Century.” August 2003. P. 171. U.S. Army Training and Doctrine Command, Fort Leavenworth, Kansas. http://smallwarsjournal.com/documents/terrorismhandbook.pdf. Accessed May 11, 2010.
  5. CDC - Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)
  6. CDC - NIOSH Pocket Guide to Chemical Hazards
  • Cooper, Paul W., Explosives Engineering, New York: Wiley-VCH, 1996. ISBN 0-471-18636-8
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.