Names | |
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Preferred IUPAC name 1,3,5,7-Tetranitro-1,3,5,7-tetrazocane | |
Other names Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine | |
Identifiers | |
3D model (JSmol) | |
ChEBI | |
ChemSpider | |
ECHA InfoCard | 100.018.418 |
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
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Properties | |
C4H8N8O8 | |
Molar mass | 296.155 g/mol |
Density | 1.91 g/cm3, solid |
Melting point | 276 to 286 °C (529 to 547 °F; 549 to 559 K) |
Explosive data | |
Shock sensitivity | Low |
Friction sensitivity | Low |
Detonation velocity | 9100 m/s |
RE factor | 1.70 |
Hazards | |
Occupational safety and health (OHS/OSH): | |
Main hazards | Explosive |
GHS labelling: | |
Danger | |
H201, H205, H241, H301, H304, H311, H319 | |
P210, P250, P280, P370+P380, P372, P373 | |
NFPA 704 (fire diamond) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
HMX, also called octogen, is a powerful and relatively insensitive nitroamine high explosive chemically related to RDX. The compound's name is the subject of much speculation, having been variously listed as High Melting Explosive, High-velocity Military Explosive, or High-Molecular-weight RDX. [1]
The molecular structure of HMX consists of an eight-membered ring of alternating carbon and nitrogen atoms, with a nitro group attached to each nitrogen atom. Because of its high mass-specific enthalpy of formation, it is one of the most potent chemical explosives manufactured, although a number of newer ones, including HNIW and ONC, are more powerful.
HMX is more complicated to manufacture than most explosives, and this confines it to specialist applications. It and RDX are both produced by the Bachmann process—nitration of hexamine using a mixture of ammonium nitrate and nitric acid in a mixture of acetic acid and acetic anhydride as solvent—with the major product determined by the specific reaction conditions. [2]
Also known as cyclotetramethylene-tetranitramine, tetrahexamine tetranitramine, or octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, HMX was first made in 1930. In 1949 it was discovered that HMX can be prepared by nitrolysis of RDX. Nitrolysis of RDX is performed by dissolving RDX in a 55% HNO3 solution, followed by placing the solution on a steambath for about six hours. [3] HMX is used almost exclusively in military applications, including as the detonator in nuclear weapons, in the form of polymer-bonded explosive, and as a solid-rocket propellant.
HMX is used in melt-castable explosives when mixed with TNT, which as a class are referred to as "octols". Additionally, polymer-bonded explosive compositions containing HMX are used in the manufacture of missile warheads and armor-piercing shaped charges.
HMX is also used in the process of perforating the steel casing in oil and gas wells. The HMX is built into a shaped charge that is detonated within the wellbore to punch a hole through the steel casing and surrounding cement out into the hydrocarbon-bearing formations. The pathway that is created allows formation fluids to flow into the wellbore and onward to the surface. [4] [5]
The Hayabusa2 space probe used HMX to excavate a hole in an asteroid in order to access material that had not been exposed to the solar wind. [6]
Ongoing research aims to reduce its sensitivity and improve some manufacturing properties. [7] [8]
HMX enters the environment through air, water, and soil because it is widely used in military and civil applications. At present, reverse-phase HPLC and more sensitive LC-MS methods have been developed to accurately quantify the concentration of HMX in a variety of matrices in environmental assessments. [9] [10]
At present, the information needed to determine if HMX causes cancer is insufficient. Due to the lack of information, EPA has determined that HMX is not classifiable as to its human carcinogenicity. [11]
The available data on the effects on human health of exposure to HMX are limited. HMX causes CNS effects similar to those of RDX, but at considerably higher doses. In one study, volunteers submitted to patch testing, which produced skin irritation. Another study of a cohort of 93 workers at an ammunition plant found no hematological, hepatic, autoimmune, or renal diseases. However, the study did not quantify the levels of exposure to HMX.
HMX exposure has been investigated in several studies on animals. Overall, the toxicity appears to be quite low. HMX is poorly absorbed by ingestion. When applied to the dermis, it induces mild skin irritation but not delayed contact sensitization. Various acute and subchronic neurobehavioral effects have been reported in rabbits and rodents, including ataxia, sedation, hyperkinesia, and convulsions. The chronic effects of HMX that have been documented through animal studies include decreased hemoglobin, increased serum alkaline phosphatase, and decreased albumin. Pathological changes were also observed in the animals' livers and kidneys.
Gas exchange rate was used as an indicator of chemical stress in Northern bobwhite quail (Colinus virginianus) eggs, and no evidence of alterations in metabolic rates associated with HMX exposure was observed. [12] No data are available concerning the possible reproductive, developmental, or carcinogenic effects of HMX. [2] [13] HMX is considered less toxic than TNT or RDX. [14] Remediating HMX-contaminated water supplies has proven to be successful. [15]
Both wild and transgenic plants can phytoremediate explosives from soil and water. [16]
RDX (abbreviation of "Research Department eXplosive" or Royal Demolition eXplosive) or hexogen, among other names, is an organic compound with the formula (CH2N2O2)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.
Trinitrotoluene, more commonly known as TNT (and 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.
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.
Phthalates, or phthalate esters, are esters of phthalic acid. They are mainly used as plasticizers, i.e., substances added to plastics to increase their flexibility, transparency, durability, and longevity. They are used primarily to soften polyvinyl chloride (PVC). Note that while phthalates are usually plasticizers, not all plasticizers are phthalates. The two terms are specific and unique and cannot be used interchangeably.
Perfluorooctanoic acid is a perfluorinated carboxylic acid produced and used worldwide as an industrial surfactant in chemical processes and as a material feedstock. PFOA is considered a surfactant, or fluorosurfactant, due to its chemical structure, which consists of a perfluorinated, n-heptyl "tail group" and a carboxylic acid "head group". The head group can be described as hydrophilic while the fluorocarbon tail is both hydrophobic and lipophobic.
Bisphenol A (BPA) is a chemical compound primarily used in the manufacturing of various plastics. It is a colourless solid which is soluble in most common organic solvents, but has very poor solubility in water. BPA is produced on an industrial scale by the condensation reaction of phenol and acetone. Global production in 2022 was estimated to be in the region of 10 million tonnes.
Torpex is a secondary explosive, 50% more powerful than TNT by mass. Torpex comprises 42% RDX, 40% TNT and 18% powdered aluminium. It was used in the Second World War from late 1942, at which time some used the names Torpex and RDX interchangeably, much to the confusion of today's historical researchers. Torpex proved to be particularly useful in underwater munitions because the aluminium component had the effect of making the explosive pulse last longer, which increased the destructive power. Besides torpedoes, naval mines, and depth charges, Torpex was only used in the Upkeep, Tallboy and Grand Slam bombs as well as the drones employed in Operation Aphrodite. Torpex has long been superseded by H6 and Polymer-bonded explosive (PBX) compositions. It is therefore regarded as obsolete and Torpex is unlikely to be encountered except in old munitions or unexploded ordnance, although a notable exception to this is the Sting Ray lightweight torpedo, which as of October 2020 remains in service with the Royal Navy and several foreign militaries. The German equivalent of Torpex was Trialen.
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.
TATB, triaminotrinitrobenzene or 2,4,6-triamino-1,3,5-trinitrobenzene is an aromatic explosive, based on the basic six-carbon benzene ring structure with three nitro functional groups (NO2) and three amine (NH2) groups attached, alternating around the ring.
Hexanitrohexaazaisowurtzitane, also called HNIW and CL-20, is a polycyclic nitroamine explosive with the formula C6H6N12O12. In the 1980s, CL-20 was developed by the China Lake facility, primarily to be used in propellants. It has a better oxidizer-to-fuel ratio than conventional HMX or RDX. It releases 20% more energy than traditional HMX-based propellants.
Dense inert metal explosive (DIME) is an experimental type of explosive that has a relatively small but effective blast radius. It is manufactured by producing a homogeneous mixture of an explosive material and small particles of a chemically inert material such as tungsten. It is intended to limit the effective distance of the explosion, to avoid collateral damage in warfare.
Triphenyl phosphate (TPhP) is the chemical compound with the formula OP(OC6H5)3. It is the simplest aromatic organophosphate. This colourless solid is the ester (triester) of phosphoric acid and phenol. It is used as a plasticizer and a fire retardant in a wide variety of settings and products.
LX-14 and LX-14-0 are polymer-bonded explosives developed by Lawrence Livermore National Laboratory and used in nuclear weapons in the United States.
Nitramide or nitroamine is a chemical compound with the molecular formula H2N−NO2. Substituted derivatives R1R2N−NO2 are termed nitramides or nitroamines as well. Organyl derivatives of nitramide, R−NH−NO2 and R2N−NO2, are widely used as explosives: examples include RDX and HMX. It is an isomer of hyponitrous acid. Nitramide can be viewed as a nitrogen analog of nitric acid, in which the hydroxyl group −OH is replaced with the amino group −NH2.
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.
Adam J. Matzger, a researcher in polymers and crystals, is the Charles G. Overberger Collegiate Professor of Chemistry at the University of Michigan.
Ecological impacts of explosives are the effects that both unexploded explosives and post-explosion by-products have on the environment. Explosive derived contaminants may have adverse effects on the environmental as well as human health.