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The Composition C family is a family of related US-specified plastic explosives consisting primarily of RDX. All can be moulded by hand for use in demolition work and packed by hand into shaped charge devices. Variants have different proportions and plasticisers and include composition C-2, composition C-3, and composition C-4. [1]
The term composition is used for any explosive material compounded from several ingredients. In particular, in the 1940s the format "Composition <letter>" was used for various compositions of the (relatively) novel explosive RDX, such as Composition B and other variants.
The original material was developed by the British during World War II, and was used in the Gammon bomb. It was standardised as Composition C when introduced to US service. This material consisted of 88.3% RDX and a mineral oil-based plasticiser and phlegmatiser. It suffered from a relatively limited range of serviceable temperatures, and was replaced by Composition C-2 around 1943, which would later be redeveloped around 1944 as Composition C-3.
Composition C-1 contained a slightly smaller proportion of RDX, but used an explosive plasticiser, which contained tetryl, nitrocellulose and a mixture of nitroaromatics produced during the manufacture of TNT (containing trinitrotoluene, dinitrotoluene, and mononitrotoluene), and a trace of solvent.
Composition C-3 was very similar to Composition C-1, but removed the solvent and varied the exact proportions of plasticisers to improve high temperature storage. It is a yellow, putty-like material. It remained a service item through the Korean War, but had marginal plasticity at the very low temperatures encountered in Korean winters, and was significantly toxic, including by vapour and skin absorption. [2] While Composition C-3 had a much wider serviceable temperature range than Composition C, it could not be stored at elevated temperatures. Consequently, it would eventually be replaced by Composition C-4. The velocity of detonation is about 7600 m/s (25,000 feet per second.)
Composition C-3 consists of 77%–85% cyclonite (RDX) and 15%–23% gel made out of liquid nitro compounds (e.g. liquid DNT and small amount of NT) and nitrocellulose or butyl phthalate and nitrocellulose. [3]
One of the first reported and tested compositions of C-3 was very similar to earlier Composition C-2 and contained 77% RDX, 3% tetryl, 4% TNT, 1% NC, 5% NT, and 10% DNT. [4] The last two compounds (they are very poor explosives) are oily liquids and plasticise the mixture. The most important later innovation of C-3 introduced the non-explosive plasticiser butyl phthalate instead of this mixture of nitro compounds. This reduced the toxicity while increasing the concentration of RDX and improving safety of use and storage. It also opened the way to begin study of new non-explosive low-toxicity plasticisers (esters of dicarboxylic acid) and binder (branched polymers).
Research on a replacement for C-3 was begun prior to 1950, but the new material, new generation of Composition C (number four, C-4), did not begin pilot production until 1956.
Since 1960 the mixture of C-4 has contained:
It is less volatile than C-3 and has less tendency to harden at low temperature. It has a density 1.48–1.60g/ml, does not become hard even at −55 °C (−67 °F), and does not exude at +77 °C (171 °F). C4 has a detonation velocity of 8092 m/s (26550 ft/s) at high density and velocity of 7550 m/s (24770 ft/s) at low density 1.48 g/ml. It is so successful that it remains in army service up to the current time without any significant changes.
RDX (abbreviation of "Research Department eXplosive") or hexogen, among other names, is an organic compound with the formula (O2N2CH2)3. It is white, odorless and tasteless, widely used as an explosive. Chemically, it is classified as a nitroamine alongside HMX, which is a more energetic explosive than TNT. It was used widely in World War II and remains common in military applications.
An explosive is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An explosive charge is a measured quantity of explosive material, which may either be composed solely of one ingredient or be a mixture containing at least two substances.
Nitroglycerin (NG), also known as trinitroglycerin (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless, oily, explosive liquid most commonly produced by nitrating glycerol with white fuming nitric acid under conditions appropriate to the formation of the nitric acid ester. Chemically, the substance is an organic nitrate compound rather than a nitro compound, but the traditional name is retained. Discovered in 1847 by Ascanio Sobrero, nitroglycerin has been used as an active ingredient in the manufacture of explosives, namely dynamite, and as such it is employed in the construction, demolition, and mining industries. It is combined with nitrocellulose to form double-based smokeless powder, which has been used as a propellant in artillery and firearms since the 1880s.
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.
Trinitrotoluene, more commonly known as TNT, more specifically 2,4,6-trinitrotoluene, and by its preferred IUPAC name 2-methyl-1,3,5-trinitrobenzene, is a chemical compound with the formula C6H2(NO2)3CH3. TNT is occasionally used as a reagent in chemical synthesis, but it is best known as an explosive material with convenient handling properties. The explosive yield of TNT is considered to be the standard comparative convention of bombs and asteroid impacts. In chemistry, TNT is used to generate charge transfer salts.
Pentaerythritol tetranitrate (PETN), also known as PENT, pentyl, PENTA, TEN, corpent, or penthrite, is an explosive material. It is the nitrate ester of pentaerythritol, and is structurally very similar to nitroglycerin. Penta refers to the five carbon atoms of the neopentane skeleton. PETN is a very powerful explosive material with a relative effectiveness factor of 1.66. When mixed with a plasticizer, PETN forms a plastic explosive. Along with RDX it is the main ingredient of Semtex and C4.
2,4,6-Trinitrophenylmethylnitramine or tetryl (C7H5N5O8) is an explosive compound used to make detonators and explosive booster charges.
C-4 or Composition C-4 is a common variety of the plastic explosive family known as Composition C, which uses RDX as its explosive agent. C-4 is composed of explosives, plastic binder, plasticizer to make it malleable, and usually a marker or odorizing taggant chemical. C-4 has a texture similar to modelling clay and can be molded into any desired shape. C-4 is relatively insensitive and can be detonated only by the shock wave from a detonator or blasting cap.
Oleum, or fuming sulfuric acid, is a term referring to solutions of various compositions of sulfur trioxide in sulfuric acid, or sometimes more specifically to disulfuric acid.
Polymer-bonded explosives, also called PBX or plastic-bonded explosives, are explosive materials in which explosive powder is bound together in a matrix using small quantities of a synthetic polymer. PBXs are normally used for explosive materials that are not easily melted into a casting, or are otherwise difficult to form.
Amatol is a highly explosive material made from a mixture of TNT and ammonium nitrate. The British name originates from the words ammonium and toluene. Similar mixtures were known as Schneiderite in France. Amatol was used extensively during World War I and World War II, typically as an explosive in military weapons such as aircraft bombs, shells, depth charges, and naval mines. It was eventually replaced with alternative explosives such as Composition B, Torpex, and Tritonal.
A plasticizer is a substance that is added to a material to make it softer and more flexible, to increase its plasticity, to decrease its viscosity, and/or to decrease friction during its handling in manufacture.
Smokeless powder, also referred to as gunpowder, is a type of propellant used in firearms and artillery that produces less smoke and less fouling when fired compared to black powder. The combustion products are mainly gaseous, compared to around 55% solid products for black powder. In addition, smokeless powder does not leave the thick, heavy fouling of hygroscopic material associated with black powder that causes rusting of the barrel.
Composition B, also known as Hexotol and Hexolite, is a high explosive consisting of castable mixtures of RDX and TNT. It is used as the main explosive filling in artillery projectiles, rockets, land mines, hand grenades and various other munitions. It was also used for the explosive lenses in the first implosion-type nuclear weapons developed by the United States.
FOX-7 or 1,1-diamino-2,2-dinitroethylene(DADNE) is an insensitive high explosive compound. It was first synthesized in 1998 by the Swedish National Defence Research Institute (FOS). The name FOX-7 is derived from the acronym of the Swedish Defence Research Agency (FOI), with the I replaced by an X to indicate an explosive, as in RDX and HMX.
Astrolite is the trade name of a family of explosives, invented by chemist Gerald Hurst in the 1960s during his employment with the Atlas Powder Company. The Astrolite family consists of two compounds, Astrolite G and Astrolite A. Both are two-part liquid-state high explosive mixtures, composed of ammonium nitrate oxidizer and hydrazine rocket fuel. The explosives were extensively studied, manufactured, and used in many countries because of their advantages of high energy, excellent performance, and wide application. They still find some use in commercial and civil blasting applications, but have mostly been superseded by cheaper and safer compounds, largely due to the expense and exceptionally poisonous nature of the hydrazine component.
2,4-Dinitrotoluene (DNT) or dinitro is an organic compound with the formula C7H6N2O4. This pale yellow crystalline solid is well known as a precursor to trinitrotoluene (TNT) but is mainly produced as a precursor to toluene diisocyanate.
Benzyl butyl phthalate (BBP) is an organic compound historically used a plasticizer, but which has now been largely phased out due to health concerns. It is a phthalate ester of containing benzyl alcohol, and n-butanol tail groups. Like most phthalates, BBP is non-volatile and remains liquid over a wide range of temperatures. It was mostly used as a plasticizer for PVC, but was also a common plasticizer for PVCA and PVB.
Diisobutyl phthalate (DIBP) is a phthalate ester having the structural formula C6H4(COOCH2CH 2)2. It is formed by the esterification of isobutanol and phthalic anhydride. This and other phthalates are used as plasticizers due to their flexibility and durability. They are found in many industrial and personal products, such as lacquers, nail polish and cosmetics. DIBP can be absorbed via oral ingestion and dermal exposure. When it comes to excretion, DIBP is first converted into the hydrolytic monoester monoisobutyl phthalate (MIBP). The primary excretory route is urine, with biliary excretion being noted in minor amounts. DIBP has lower density and freezing point than the related compound dibutyl phthalate (DBP).
Explosive materials are produced in numerous physical forms for their use in mining, engineering, or military applications. The different physical forms and fabrication methods are grouped together in several use forms of explosives.
The detainee was trained to use the Kalashnikov rifle, rocket propelled grenades, hand grenades, land mines, Composition-3 (C-3) and Composition-4 (C-4) explosives.
Composition-3 (C-3) and Composition-4 (C-4) explosives, Semtex.
