Hexogen (also Cyclotrimethylentrinitramin, Cyclonit, T4 and R.D.X. – Research department explosive) is an high-explosive, poisonous explosive, which was manufactured during the Second World War in large quantities and which is still used. The complete name of Hexogen reads Hexahydro-1,3,5-trinitro-1,3,5-triazin.
Structure and characteristics
Hexogen, (CH2-N-NO2) 3, C3H6N6O6, mol mass 222.117 g/mol
Hexogen (Cyclotrimethylentrinitramin) is a colorless, crystalline solid with a density of 1,82 g/cm and a melting point of 204 “°C. The Hexogen molecule has a circular structure with three nitrogen atoms (Triazinring), it is thus a Heterocyclus.
The crystal structure is orthorhombisch, space group Pbca; a=13,22 b=11,61 c=10,75 Z=8.
Mohs hardness: 2,5
The steam pressure with 20″°C is 5.5 10-9 mbar. The solubility in water with 20 “°C amounts to 42 mg/L.
In the Hexogen existing the Nitrogruppen (- NO2) step in many explosives up, for example also in the TNT or – as group of nitric acid esters (- O-NO2) – in the gun cotton and in the Nitroglycerin.
Hexogen has a detonation speed of 8.500 m/s and about 150% Kraft of TNT and is the main part of the Plastiksprengstoffe C4 and Semtex.
Its production and handling led in the past already to contaminations of drinking water and environmental.
Hexogen develops with the reaction of Hexamethylentetramin with nitric acid HNO3.
One wins Hexogen by careful addition of Hexamethylentetramin (Urotropin, hexadecimal min, drying white spirits) to highly concentrated nitric acid (98-99%) with approx. 15 degrees Celsius and following water dilution (nitrating). The relationship from ml acid to gram of hexadecimal min is 11:1. Technical procedures work modified using additives, which e.g. bind water or supply necessary formaldehyde additionally. (Hexadecimal min is developed a condensation product made of ammonia and formaldehyde, in aqueous solution.)
Hexogen is considered as particularly strong and high-explosive explosive and is a component of many common kinds of explosive, for example C4 and Torpex. It is shifted usually with plasticization means or used in mixtures with other explosives, in order to lower the explosiveness and to make so a safe handling possible.
Pure Hexogen is highly explosive and should be stored therefore on cool places damp in the dry condition or in water. In the absolutely dry condition small activation energies (30″°C or easy contact) are sufficient for igniting. Hexogen is never used therefore without Plastifizierer such as polyisobutilene, polyethylene, wax, Knetmasse or the like.
For the ignition of these Plastiksprengstoffe a #6 blasting cap is normally used.
Hexogen was described 1898 of the citizen of Berlin chemist G.F.Henning as output product for pharmaceutical preparations in a German realm Reich. H. Brunswig recognized likewise in Germany 1916 for the first time the high-explosive characteristics and could it in 2 patents be protected. In the year 1920 one investigated in the office for military attempt in Berlin the substance more near and designated her for Hexogen. The manufacturing processes were however insufficient. Only into the 1930er years just as 4 new procedures were developed in Germany and the Hexogen under different pseudonyms as SH, e or W-salt in 2. World war applied. Similar procedures were developed also with the war opponent (e.g. .das brook man procedures in the USA). Today different combinations (so e.g. “Torpex” from 40% Hexogen, 42% TNT and 18% aluminum) are used, because the Hexogen apart from a high chemical and thermal stability represents also to one of the most explosive all explosives during high work. The substance is therefore today the most important high-explosive military explosive, which is used. It was also a component in one of the first Plastiksprengstoffe.
Literature: J.Gartz: Culture history of the Explosivstoffe.E.S.Mittler & Sohn.Hamburg.2006.