Plastic explosives

Semtex -H as an example of a plastic explosive

As plastic explosives or plastic explosives are explosives referred to by their plasticity excel are so soft and malleable.

The term "plastic explosive" is an incorrect loan translation of the English term plastic explosive . In short, “ plastic ”, the noun for plastics based on polymers , is used. The term “plastic explosives”, however, would be correct in the sense of the original meaning. Plastic explosives are also not to be confused with polymer-bound explosives or plastic-bound explosives.

history

PE-808 plastic explosives, a British pre-war invention by the Nobel Division, Imperial Chemical Industries , consisted of explosive gelatine , a high-explosive substance, phlegmatized and plasticized with nitrotoluene . A mixture of 61.5% nitroglycerin, 16% nitrocellulose, 22% nitrotoluene and 0.5% magnesium carbonate produced a stable, waterproof and impact-resistant, putty-like material that could be filled into containers or painted directly on an object. This created an effective resistance weapon that could be ideally used to sabotage train tracks or other vulnerable targets.

Preparation for the demolition of an anchor chain with C4 (training with US Navy)

PE 808 was yellow-brown and was packed in sticks of 75 mm × 30 mm, each weighing 100 g, in wax paper sleeves. It had a characteristic marzipan smell (like mononitrotoluene), which caused severe headaches when inhaled (physiological effect of nitroglycerine). Was detonated PE 808 with a compositing Explosive- (CE) - tetryl - booster charge and introduced therein No.27-Mk1- detonator . The detonator was a 45 mm mm long, thin aluminum tube with an outer diameter of about 6.3, having a base charge pressed Tetryl and a charge of having at the closed end styphnate überschichtetem lead azide -Bleistyphnat-bang set contained. The detonator in turn was prepared by a suitable igniter reacted, for example by a pencil detonator (chemical mechanical time fuse) or by the inserted into the detonator and to gewürgte therein Sicherheitsanzündschnur (such as the British "Nr. 11 safety fuse"). This fuse consisted of a black powder core, which was wrapped in several layers of pitch-impregnated jute fabric and thus waterproofed. It burned at 0.6 meters per minute, which made it very easy to make a delay detonator.

A whole range of hexogen-based explosives were introduced during and shortly after World War II (British PE1, PE2, PE3, PE / A, PE4, US C, C2, C3, German Plastit W and Hexoplast). C3 was very effective, but fragile in the cold. In the 1950s, the well-known C4 , also based on hexogen, was developed with polyisobutylene and di (2-ethylhexyl) sebacate as binders and plasticizers. Semtex is another plastic explosive developed by the Ostböhmische Chemiewerke VCHZ Synthesia in Pardubice-Semtin, based on nitropenta and its mixtures with hexogen.

use

Remnants of a pipe bomb filled with the plastic explosive C4 from an FBI experimental setup

Plastic explosives are used, among other things, to detonate steel in cutting charges . The ease of use has made plastic explosives an explosive used by special military forces, but also by terrorists. Due to their higher manufacturing cost, plastic explosives are rarely used in mining or to make bombs. Plastic explosives are rarely used to demolish structures, but rather explosives with a "pushing" effect, such as ammongelite .

mark

Plastic explosives are marked during production by adding odorous substances and / or metal shavings ( English tagging agent or taggant ) in order to be able to find them more easily with sniffer dogs and detection devices ( X-ray ).

Such taggants are easily smellable substances with a relatively high vapor pressure such as:

• 2,3-Dimethyl-2,3-dinitrobutane (DMNB, DMDNB, C ₆ H ₁₂ N ₂ O ₄ ):> 0.1% by weight
• 4-nitrotoluene ( p -MNT):> 0.5% by weight
• 2-nitrotoluene ( o -MNT):> 0.5% by weight
• Ethylene glycol dinitrate (EGDN):> 0.2% by weight

The manufacture of malleable explosives without a marker is prohibited in most states. This ban is regulated in the Convention on the Marking of Plastic Explosives for the Purpose of Detection , which was also signed by Germany, Austria and Switzerland and came into force on June 21, 1998. All three states have also declared themselves a “producer state”, that is, the country where plastic explosives are manufactured.

In Germany, marking was regulated by amending the First Ordinance on the Explosives Act. Thereafter, unmarked explosives had to be used or destroyed according to § 6a by December 31, 2013.

According to Bureau of Alcohol, Tobacco, Firearms, and Explosives, Justice §555.180 , since April 26, 1996, only malleable explosives (plastic explosives) that contain a marking substance in a specified minimum concentration may be used in the USA.

Web links

• Basic knowledge on explosives (accessed on May 7, 2020)
• Convention on the Marking of Plastic Explosives for the Purpose of Detection (accessed May 7, 2020)
• Ordinance on Explosive Substances (accessed May 7, 2020)
• On the toxicology of military-specific explosives and their decomposition products (accessed on May 7, 2020)

Individual evidence

1. ↑ Wolfgang Legrum: Fragrances, between stink and fragrance , Vieweg + Teubner Verlag (2011) pp. 166–167, ISBN 978-3-8348-1245-2 .
2. ↑ Jehuda Yinon: Forensic and Environmental Detection of Explosives . John Wiley & Sons, 1999, ISBN 978-0-471-98371-2 , pp. 167 ( limited preview in Google Book search).
3. ↑ External identifiers or database links for 2,3-dimethyl-2,3-dinitrobutane : CAS number: 3964-18-9, EC number: 223-569-9, ECHA InfoCard: 100.021.428 , PubChem : 77577 , ChemSpider : 69982 , Wikidata : Q3267064 .
4. ↑ Federal Law Gazette III No. 135/1999