Magnesium/Teflon/Viton (MTV) is a pyrolant. Teflon and Viton are trademarks of DuPont for polytetrafluoroethylene, (C2F4)n, and fluoroelastomer, (CH2CF2)n(CF(CF3)CF2)n.
 | This section needs expansion. You can help by adding to it. (January 2016) |
 |
Thermites based on magnesium/Teflon/Viton, aka MTV-compositions, have been in use since the 1950s as payloads in infrared decoy flare applications. See also Countermeasures. Derived from the acronym MTV is the expression "MTV-Flare" for pyrotechnic infrared decoy flares.
Whereas in conventional visual pyrotechnic illuminants sodium nitrate, NaNO3, is used as an oxidizer, in MTV compositions the polytetrafluoroethylene, (C2F4)n, acts as fluorine source. The very high reaction enthalpy, , upon combustion of magnesium with PTFE is based on the formation of magnesium fluoride, having a very high negative enthalpy of formation ( = −1124 kJ mol−1):
As much carbon and heat are released upon combustion of MTV the combustion flame can be described as a grey body of high emissivity. [1]
Depending on stoichiometry, MTV displays varying burn rates and yields different reaction products. With constant Viton-content the burn rate increases exponentially with increasing magnesium content. [2] Nevertheless the burn rate of MTV, as is the case with many metallized pyrotechnic compositions is strongly dependent on the specific surface area of the metal fuel, that are particle morphology and dimensions. Generally magnesium powder having a high specific surface area will exhibit a higher burn rate than those having a smaller specific area. The main reaction products for MTV at Mg contents between 30 and 65 wt% are magnesium fluoride, soot and vaporized magnesium. [3]
For aerial decoy flares magnesium rich compositions are used with Mg contents between 55 and 65 wt%. At these stoichiometries only a part of the applied Mg reacts with the PTFE. The surplus Mg is vaporised and reacts with the atmospheric oxygen; likewise the thermally excited soot reacts with the atmospheric oxygen:
Pyrotechnic compositions based on magnesium/polytetrafluoroethylene with stoichiometries from 25 wt% to 90 wt% magnesium are, according to German explosive legislation, the Koenen test (steel sleeve test), and BAM impact test, explosive substances. Due to their sensitivity and their reaction behaviour these substances are categorized as group 1.1.2. [4] MTV compositions explode at minimum confinement (also self confinement) at relative low amounts. MTV compositions are sensitive toward thermal ignition. In addition MTV compositions in loose and pressed state are extraordinarily sensitive to friction and electrostatic discharges (ESD). [5] Hence, suitable measures have to be taken to avoid ESD while processing and handling of MTV.
Since aircraft and helicopters could (and still can) counter surface-to-air and air-to-air missiles with the substance, MTV was a classified issue until the mid-1980s. It was not until 1997 that the U.S. government released a formerly classified invention, U.S. patent 5,679,921 (filing year 1957), that originally described the properties and applications of MTV. [6]
Although missile development has improved seeker countermeasures against MTV flares there are still numerous missile systems fielded worldwide based on 1st generation technology. Hence MTV flares are still not obsolete in fighting unknown threats. Together with advanced spectral flares (see countermeasures) they are part of the so-called "cocktail solution". [7]
E.-C. Koch, Metal-Fluorocarbon Based Energetic Materials, Wiley-VCH, 2012, 360 pages
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene, and has numerous applications because it is chemically inert. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from DuPont, which originally discovered the compound in 1938.
Ytterbium is a chemical element; it has symbol Yb and atomic number 70. It is a metal, the fourteenth and penultimate element in the lanthanide series, which is the basis of the relative stability of its +2 oxidation state. Like the other lanthanides, its most common oxidation state is +3, as in its oxide, halides, and other compounds. In aqueous solution, like compounds of other late lanthanides, soluble ytterbium compounds form complexes with nine water molecules. Because of its closed-shell electron configuration, its density, melting point and boiling point are much lower than those of most other lanthanides.
A flare, also sometimes called a fusée, fusee, or bengala, bengalo in several European countries, is a type of pyrotechnic that produces a bright light or intense heat without an explosion. Flares are used for distress signaling, illumination, or defensive countermeasures in civilian and military applications. Flares may be ground pyrotechnics, projectile pyrotechnics, or parachute-suspended to provide maximum illumination time over a large area. Projectile pyrotechnics may be dropped from aircraft, fired from rocket or artillery, or deployed by flare guns or handheld percussive tubes.
Thermite is a pyrotechnic composition of metal powder and metal oxide. When ignited by heat or chemical reaction, thermite undergoes an exothermic reduction-oxidation (redox) reaction. Most varieties are not explosive, but can create brief bursts of heat and high temperature in a small area. Its form of action is similar to that of other fuel-oxidizer mixtures, such as black powder.
Pyrotechnics is the science and craft of creating such things as fireworks, safety matches, oxygen candles, explosive bolts and other fasteners, parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demolition. This trade relies upon self-contained and self-sustained exothermic chemical reactions to make heat, light, gas, smoke and/or sound. The name comes from the Greek words pyr ("fire") and tekhnikos.
Magnesium diboride is the inorganic compound with the formula MgB2. It is a dark gray, water-insoluble solid. The compound has attracted attention because it becomes superconducting at 39 K (−234 °C). In terms of its composition, MgB2 differs strikingly from most low-temperature superconductors, which feature mainly transition metals. Its superconducting mechanism is primarily described by BCS theory.
MTV is an American cable channel.
A squib is a miniature explosive device used in a wide range of industries, from special effects to military applications. It resembles a tiny stick of dynamite, both in appearance and construction, but has considerably less explosive power. A squib consists of two electrical leads separated by a plug of insulating material; a small bridge wire or electrical resistance heater; and a bead of heat-sensitive chemical composition, in which the bridge wire is embedded. They can be used to generate mechanical force to shatter or propel various materials; and for pyrotechnic effects for film and live theatrics.
Flash powder is a pyrotechnic composition, a mixture of oxidizer and metallic fuel, which burns quickly (deflagrates) and produces a loud noise regardless of confinement. It is widely used in theatrical pyrotechnics and fireworks and was once used for flashes in photography.
A pyrotechnic colorant is a chemical compound which causes a flame to burn with a particular color. These are used to create the colors in pyrotechnic compositions like fireworks and colored fires. The color-producing species are usually created from other chemicals during the reaction. Metal salts are commonly used; elemental metals are used rarely.
Nano-thermite or super-thermite is a metastable intermolecular composite (MIC) characterized by a particle size of its main constituents, a metal fuel and oxidizer, under 100 nanometers. This allows for high and customizable reaction rates. Nano-thermites contain an oxidizer and a reducing agent, which are intimately mixed on the nanometer scale. MICs, including nano-thermitic materials, are a type of reactive materials investigated for military use, as well as for general applications involving propellants, explosives, and pyrotechnics.
Carbon monofluoride (CF, CFx, or (CF)n), also called polycarbon monofluoride (PMF), polycarbon fluoride, poly(carbon monofluoride), and graphite fluoride, is a material formed by high-temperature reaction of fluorine gas with graphite, charcoal, or pyrolytic carbon powder. It is a highly hydrophobic microcrystalline powder. Its CAS number is . In contrast to graphite intercalation compounds it is a covalent graphite compound.
A pyrotechnic composition is a substance or mixture of substances designed to produce an effect by heat, light, sound, gas/smoke or a combination of these, as a result of non-detonative self-sustaining exothermic chemical reactions. Pyrotechnic substances do not rely on oxygen from external sources to sustain the reaction.
A pyrolant is an energetic material that generates hot flames upon combustion. Pyrolants are metal-based pyrotechnic compositions containing virtually any oxidizer. The term was originally coined by Kuwahara in 1992, in a paper on magnesium/Teflon/Viton, to distinguish between compositions that serve as propellants and those yielding hot flames which are not necessarily suitable for propellant purposes.
A flare or decoy flare is an aerial infrared countermeasure used by an aircraft to counter an infrared homing ("heat-seeking") surface-to-air missile or air-to-air missile. Flares are commonly composed of a pyrotechnic composition based on magnesium or another hot-burning metal, with burning temperature equal to or hotter than engine exhaust. The aim is to make the infrared-guided missile seek out the heat signature from the flare rather than the aircraft's engines.
In the U.S. military, reactive materials (RM) are a new class of materials currently being investigated by the Office of Naval Research and others as a means to increase the lethality of direct-hit or fragmentation warheads. Reactive materials are similar to insensitive high explosives, but are usually thermite-like pyrotechnic compositions of two or more nonexplosive solid materials, which stay inert and do not react with each other until subjected to a sufficiently strong mechanical, electrical or laser stimulus, after which they undergo fast burning or explosion with release of high amount of chemical energy in addition to their kinetic energy. Fragments or projectiles made of such materials have therefore greater damaging effect than inert ones, with expected lethality increase up to 500%.
Chemring Group plc is a global business providing a range of advanced technology products and services to the aerospace, defence and security markets. Chemring has extensive operations in the Americas, Europe, Middle East and Asia.
Crane Army Ammunition Activity (CAAA) in Crane, Indiana produces and provides conventional munitions requirements in support of United States Army and Joint Force readiness. It is one of 17 installations of the Joint Munitions Command and one of 23 organic industrial bases under the U.S. Army Materiel Command, which include arsenals, depots, activities and ammunition plants. Established in October 1977, it is located on Naval Support Activity Crane.
An environmentally friendly red-light flare was a pyrotechnic (firework) flare which used lithium-based formulations that emitted red light. A flare is used for signaling, illumination, or defensive countermeasures in civilian or military applications. It is based on a non-hygroscopic dilithium nitrogen-rich salt that served as an oxidizer and red colorant. The U.S. Army Research Laboratory and the Ludwig Maximilian Institution were credited as the research facilities for developing this product announced in January 2018.
A hydrofluoric acid burn is a chemical burn from hydrofluoric acid. Where it contacts the skin it results in significant pain, swelling, redness, and skin breakdown. If the fumes are breathed in swelling of the upper airway and bleeding may occur. Complications can include electrolyte, heart, lung, kidney, and neurological problems.
