PETN
Encyclopedia
Pentaerythritol tetranitrate (PETN), also known as PENT, PENTA, TEN, corpent, penthrite (or—rarely and primarily in German—as nitropenta), is the nitrate
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...

 ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...

 of pentaerythritol
Pentaerythritol
Pentaerythritol is the organic compound with the formula C5H12O4. This white, crystalline polyol with the neopentane backbone is a versatile building block for the preparation of many polyfunctionalized compounds such as the explosive PETN and pentaerythritol tetraacrylate...

. Penta refers to the five carbon atoms of the neopentane
Neopentane
Neopentane, also called dimethylpropane, is a double-branched-chain alkane with five carbon atoms. Neopentane is an extremely flammable gas at room temperature and pressure which can condense into a highly volatile liquid on a cold day, in an ice bath, or when compressed to a higher...

 skeleton.

PETN is most well known as an explosive. It is one of the most powerful high explosives
Explosive material
An explosive material, also called 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...

 known, with a relative effectiveness factor
Relative effectiveness factor
Relative effectiveness factor or R.E. factor is a measurement of an explosive's power for military demolitions purposes. It is used to compare an explosive's effectiveness relative to TNT by weight only. This enables engineers to substitute one explosive for another when they are calculating...

 of 1.66.

PETN mixed with a plasticizer
Plasticizer
Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effects and results are...

 forms a plastic explosive
Plastic explosive
Plastic explosive is a specialised form of explosive material. It is a soft and hand moldable solid material. Plastic explosives are properly known as putty explosives within the field of explosives engineering....

. As a mixture with RDX
RDX
RDX, an initialism for Research Department Explosive, is an explosive nitroamine widely used in military and industrial applications. It was developed as an explosive which was more powerful than TNT, and it saw wide use in WWII. RDX is also known as cyclonite, hexogen , and T4...

 and other minor additives, it forms another plastic explosive called Semtex
Semtex
Semtex is a general-purpose plastic explosive containing RDX and PETN. It is used in commercial blasting, demolition, and in certain military applications. Semtex became notoriously popular with terrorists because it was, until recently, extremely difficult to detect, as in the case of Pan Am...

 as well. The compound was discovered in the bombs used by the 2001 Shoe Bomber, in the 2009 Christmas Day bomb plot, and in the 2010 cargo plane bomb plot. On 7 September 2011, a bomb suspected to have used PETN exploded near the High Court of Delhi in India claiming 13 lives and injuring more than 70.

It is also used as a vasodilator
Vasodilation
Vasodilation refers to the widening of blood vessels resulting from relaxation of smooth muscle cells within the vessel walls, particularly in the large arteries, smaller arterioles and large veins. The process is essentially the opposite of vasoconstriction, or the narrowing of blood vessels. When...

 drug to treat certain heart conditions, such as for management of angina
Angina
Angina pectoris, commonly known as angina, is chest pain due to ischemia of the heart muscle, generally due to obstruction or spasm of the coronary arteries . Coronary artery disease, the main cause of angina, is due to atherosclerosis of the cardiac arteries...

.

History

Penthrite was first synthesized in 1891 by Bernhard Tollens
Bernhard Tollens
Bernhard Christian Gottfried Tollens was a German chemist.- Life and work :Tollens attended school at the Gelehrtenschule des Johanneums in Hamburg where he was influenced by his science teacher, Karl Möbius. After graduating in 1857, Tollens started an apprenticeship in pharmacy...

 and P. Wigand by nitration
Nitration
Nitration is a general chemical process for the introduction of a nitro group into a chemical compound. The dominant application of nitration is for the production of nitrobenzene, the precursor to methylene diphenyl diisocyanate...

 of pentaerythritol. The production of PETN started in 1912, when it was patented by the German government. PETN was used by the German Army in .

Properties

PETN is practically insoluble
Solubility
Solubility is the property of a solid, liquid, or gaseous chemical substance called solute to dissolve in a solid, liquid, or gaseous solvent to form a homogeneous solution of the solute in the solvent. The solubility of a substance fundamentally depends on the used solvent as well as on...

 in water (0.01 g/100 ml at 50 °C), weakly soluble in common nonpolar solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...

s such as aliphatic hydrocarbon
Aliphatic compound
In organic chemistry, aliphatic compounds are acyclic or cyclic, non-aromatic carbon compounds.Thus, aliphatic compounds are opposite to aromatic compounds.- Structure :...

s or tetrachloromethane
Carbon tetrachloride
Carbon tetrachloride, also known by many other names is the organic compound with the formula CCl4. It was formerly widely used in fire extinguishers, as a precursor to refrigerants, and as a cleaning agent...

, but soluble in some other organic solvents, particularly in acetone
Acetone
Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...

 (about 15 g/100 g of the solution at 20 °C, 55 g/100 g at 60 °C) and dimethylformamide
Dimethylformamide
Dimethylformamide is an organic compound with the formula 2NCH. Commonly abbreviated as DMF , this colourless liquid is miscible with water and the majority of organic liquids. DMF is a common solvent for chemical reactions...

 (40 g/100 g of the solution at 40 °C, 70 g/100 g at 70 °C). PETN forms eutectic
Eutectic system
A eutectic system is a mixture of chemical compounds or elements that has a single chemical composition that solidifies at a lower temperature than any other composition. This composition is known as the eutectic composition and the temperature is known as the eutectic temperature...

 mixtures with some liquid or molten aromatic
Aromaticity
In organic chemistry, Aromaticity is a chemical property in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. The earliest use of the term was in an article by August...

 nitro compound
Nitro compound
Nitro compounds are organic compounds that contain one or more nitro functional groups . They are often highly explosive, especially when the compound contains more than one nitro group and is impure. The nitro group is one of the most common explosophores used globally...

s, e.g. trinitrotoluene (TNT) or tetryl
Tetryl
2,4,6-Trinitrophenylmethylnitramine commonly referred to as tetryl is a sensitive explosive compound used to make detonators and explosive booster charges....

. Due to its highly symmetrical structure, PETN is resistant to attack by many chemical reagent
Reagent
A reagent is a "substance or compound that is added to a system in order to bring about a chemical reaction, or added to see if a reaction occurs." Although the terms reactant and reagent are often used interchangeably, a reactant is less specifically a "substance that is consumed in the course of...

s; it does not hydrolyze
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...

 in water at room temperature or in weaker alkaline
Alkalinity
Alkalinity or AT measures the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution...

 aqueous solution
Aqueous solution
An aqueous solution is a solution in which the solvent is water. It is usually shown in chemical equations by appending aq to the relevant formula, such as NaCl. The word aqueous means pertaining to, related to, similar to, or dissolved in water...

s. Water at 100° or above causes hydrolysis
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...

 to dinitrate; presence of 0.1% nitric acid
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...

 accelerates the reaction. Addition of TNT and other aromatic nitro
Nitro compound
Nitro compounds are organic compounds that contain one or more nitro functional groups . They are often highly explosive, especially when the compound contains more than one nitro group and is impure. The nitro group is one of the most common explosophores used globally...

 derivatives lowers thermal stability
Thermal stability
Thermal stability is the stability of a molecule at high temperatures; i.e. a molecule with more stability has more resistance to decomposition at high temperatures....

 of PETN.

The chemical stability
Chemical stability
Chemical stability when used in the technical sense in chemistry, means thermodynamic stability of a chemical system.Thermodynamic stability occurs when a system is in its lowest energy state, or chemical equilibrium with its environment. This may be a dynamic equilibrium, where individual atoms...

 of PETN is of interest, because of the use of PETN in aging stockpiles of weapons. A review has been published. Neutron radiation
Neutron radiation
Neutron radiation is a kind of ionizing radiation which consists of free neutrons. A result of nuclear fission or nuclear fusion, it consists of the release of free neutrons from atoms, and these free neutrons react with nuclei of other atoms to form new isotopes, which, in turn, may produce...

 degrades PETN, producing carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 and some pentaerythritol dinitrate and trinitrate
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...

. Gamma radiation increases the thermal decomposition
Thermal decomposition
Thermal decomposition, or thermolysis, is a chemical decomposition caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes....

 sensitivity of PETN, lowers melting point by few degrees Celsius, and causes swelling of the samples. Like other nitrate esters, the primary degradation
Degradation
Degradation may refer to;* Biodegradation, the processes by which organic substances are broken down by living organisms* Cashiering or degradation ceremony, a ritual performed when cleric is deprived of office or a knight is stripped of the honour...

 mechanism is the loss of nitrogen dioxide
Nitrogen dioxide
Nitrogen dioxide is the chemical compound with the formula it is one of several nitrogen oxides. is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year. This reddish-brown toxic gas has a characteristic sharp, biting odor and is a prominent...

; this reaction is autocatalytic.. Studies were performed on thermal decomposition
Thermal decomposition
Thermal decomposition, or thermolysis, is a chemical decomposition caused by heat. The decomposition temperature of a substance is the temperature at which the substance chemically decomposes....

 of PETN.

In the environment, PETN undergoes biodegradation
Biodegradation
Biodegradation or biotic degradation or biotic decomposition is the chemical dissolution of materials by bacteria or other biological means...

. Some bacteria denitrate PETN to trinitrate and then dinitrate, which is then further degraded. PETN has low volatility
Volatility (chemistry)
In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.The term is primarily...

 and low solubility in water, and therefore has low bioavailability
Bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is used to describe the fraction of an administered dose of unchanged drug that reaches the systemic circulation, one of the principal pharmacokinetic properties of drugs. By definition, when a medication is administered...

 for most organisms. Its toxicity
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...

 is relatively low, and its transdermal
Transdermal
Transdermal is a route of administration wherein active ingredients are delivered across the skin for systemic distribution. Examples include transdermal patches used for medicine delivery, and transdermal implants used for medical or aesthetic purposes....

 absorption also seems to be low. It poses a threat for aquatic organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...

s. It can be degraded to pentaerythritol by iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...

 metal.

Production

This compound is produced by reaction of pentaerythritol
Pentaerythritol
Pentaerythritol is the organic compound with the formula C5H12O4. This white, crystalline polyol with the neopentane backbone is a versatile building block for the preparation of many polyfunctionalized compounds such as the explosive PETN and pentaerythritol tetraacrylate...

 with concentrated nitric acid
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...

. In this reaction, it forms a precipitate. The crude can be recrystallized from acetone to give processable crystals.
C(CH2OH)4 + 4 HNO3 → C(CH2ONO2)4 + 4 H2O


PETN is manufactured by numerous manufacturers as a powder about the consistency of fine popcorn salt, or together with nitrocellulose
Nitrocellulose
Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...

 and plasticizer
Plasticizer
Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effects and results are...

 as thin plasticized sheets (e.g. Primasheet
Primasheet
Primasheet is a rubberized sheet explosive material similar to Detasheet. Manufactured by Ensign-Bickford Aerospace & Defense Company Primasheet comes in two varieties: Primasheet 1000 is PETN based and Primasheet 2000 is RDX based...

 1000 or Detasheet
Detasheet
Detasheet is a flexible rubberized explosive, somewhat similar to plastic explosives, originally manufactured by DuPont. Its ingredients are PETN with nitrocellulose and a binder.- Properties :...

). PETN residues are easily detectable in hair of people handling it. The highest residue retention is on black hair; some residues remain present even after washing.

Explosive use

The most common use of PETN is as an explosive with high brisance
Brisance
Brisance is the shattering capability of an explosive. It is a measure of the rapidity with which an explosive develops its maximum pressure. The term originates from the French verb "briser", which means to break or shatter...

. It is more difficult to detonate than primary explosives, so dropping or igniting it will typically not cause an explosion (at atmospheric pressure
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...

 it is difficult to ignite and burns relatively slowly), but is more sensitive to shock and friction than other secondary explosives such as TNT or tetryl
Tetryl
2,4,6-Trinitrophenylmethylnitramine commonly referred to as tetryl is a sensitive explosive compound used to make detonators and explosive booster charges....

. Under certain conditions a deflagration to detonation transition
Deflagration to detonation transition
Deflagration to detonation transition refers to a phenomenon in ignitable mixtures of a flammable gas and air when a sudden transition takes place from a deflagration type of combustion to a detonation type of combustion...

 can occur.

It is rarely used alone, but primarily used in booster
Explosive booster
An explosive booster acts as a bridge between a low energy explosive and a low sensitivity explosive such as TNT. It increases the explosive shockwave from an initiating explosive to the degree sufficient to detonate the secondary charge.Unlike C4 plastic explosive, not all explosives can be...

 and bursting charges
Burst charge
In fireworks, a burst charge is an energetic pyrotechnic mixture placed in a shell which is ignited when the shell reaches the desired height in order to pass fire to and spread the stars. Burst charge compositions are usually coated onto rice hulls or other low-density fillers, which increases...

 of small caliber
Caliber
In guns including firearms, caliber or calibre is the approximate internal diameter of the barrel in relation to the diameter of the projectile used in it....

 ammunition
Ammunition
Ammunition is a generic term derived from the French language la munition which embraced all material used for war , but which in time came to refer specifically to gunpowder and artillery. The collective term for all types of ammunition is munitions...

, in upper charges of detonator
Detonator
A detonator is a device used to trigger an explosive device. Detonators can be chemically, mechanically, or electrically initiated, the latter two being the most common....

s in some land mine
Land mine
A land mine is usually a weight-triggered explosive device which is intended to damage a target—either human or inanimate—by means of a blast and/or fragment impact....

s and shells, and as the explosive core of detonation cord. PETN is the least stable of the common military explosives, but can be stored without significant deterioration for longer than nitroglycerin or nitrocellulose
Nitrocellulose
Nitrocellulose is a highly flammable compound formed by nitrating cellulose through exposure to nitric acid or another powerful nitrating agent. When used as a propellant or low-order explosive, it is also known as guncotton...

.

During World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, PETN was most importantly used in exploding-bridgewire detonator
Exploding-bridgewire detonator
The exploding-bridgewire detonator is a type of detonator used to initiate the detonation reaction in explosive materials, similar to a blasting cap in that it is fired using an electric current...

s for the atomic bombs. These exploding-bridgewire detonators gave more precise detonation, compared with primacord
Primacord
Primacord is a registered trademark of detonating cord used in blasting, originally manufactured by the Ensign-Bickford Company. Ensign Bickford sold the trademark to Dyno Nobel Inc in 2003 and it is now manufactured in Graham, Kentucky...

. PETN was used for these detonators because it was safer than primary explosives like lead azide: while it was sensitive, it would not detonate below a threshold amount of energy. Exploding bridgewires containing PETN remain used in current nuclear weapons. In spark detonators, PETN is used to avoid the need for primary explosives; the energy needed for a successful direct initiation of PETN by an electric spark
Electric spark
An electric spark is a type of electrostatic discharge that occurs when an electric field creates an ionized electrically conductive channel in air producing a brief emission of light and sound. A spark is formed when the electric field strength exceeds the dielectric field strength of air...

 ranges between 10–60 mJ.

Its basic explosion characteristics are:
  • Explosion energy: 5810 kJ/kg (1390 kcal/kg), so 1 kg of PETN has the energy of 1.24 kg TNT.
  • Detonation velocity: 8350 m/s (1.73 g/cm3), 7910 m/s (1.62 g/cm3), 7420 m/s (1.5 g/cm3), 8500 m/s (pressed in a steel tube)
  • Volume of gases produced: 790 dm3/kg (other value: 768 dm3/kg)
  • Explosion temperature: 4230 °C
  • Oxygen balance
    Oxygen balance
    Oxygen balance is an expression that is used to indicate the degree to which an explosive can be oxidized. If an explosive molecule contains just enough oxygen to form carbon dioxide from carbon, water from hydrogen molecules, all of its sulfur dioxide from sulfur, and all metal oxides from metals...

    : -6.31 atom -g/kg
  • Melting point
    Melting point
    The melting point of a solid is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard atmospheric pressure...

    : 141.3 °C (pure), 140–141 °C (technical)
  • Trauzl lead block test
    Trauzl lead block test
    The Trauzl lead block test, also called the Trauzl test or just Trauzl, is a test used to measure the strength of explosive materials. It was developed by Isidor Trauzl in 1885....

    : 523 cm3 (other values: 500 cm3 when sealed with sand, or 560 cm3 when sealed with water)
  • Critical diameter (minimal diameter of a rod that can sustain detonation propagation): 0.9 mm for PETN at 1 g/cm3, smaller for higher densities (other value: 1.5 mm)

In mixtures

PETN is used in a number of compositions. It is a major ingredient of the Semtex
Semtex
Semtex is a general-purpose plastic explosive containing RDX and PETN. It is used in commercial blasting, demolition, and in certain military applications. Semtex became notoriously popular with terrorists because it was, until recently, extremely difficult to detect, as in the case of Pan Am...

 plastic explosive
Plastic explosive
Plastic explosive is a specialised form of explosive material. It is a soft and hand moldable solid material. Plastic explosives are properly known as putty explosives within the field of explosives engineering....

. It is also used as a component of pentolite
Pentolite
Pentolite is a high explosive used for military and civilian purposes e.g. warheads and booster charges.Military pentolite comprises a mixture of 50% PETN and 50% TNT. A 50:50 mixture has a density of 1.65 g/cm3 and a detonation velocity of 7400 m/s. Civilian pentolite sometimes contains a lower...

, a 50/50 blend with TNT; a shaped charge
Shaped charge
A shaped charge is an explosive charge shaped to focus the effect of the explosive's energy. Various types are used to cut and form metal, to initiate nuclear weapons, to penetrate armor, and in the oil and gas industry...

 of 8 ounce (0.226796184 kg) of pentolite, used in the M9A1 (bazooka)
Bazooka
Bazooka is the common name for a man-portable recoilless rocket antitank weapon, widely fielded by the U.S. Army. Also referred to as the "Stovepipe", the innovative bazooka was amongst the first-generation of rocket propelled anti-tank weapons used in infantry combat...

 rockets, can penetrate up to 5 inches (127 mm) of armor. The XTX8003 extrudable explosive, used in the W68
W68
The W68 warhead was the warhead used on the UGM-73 Poseidon SLBM missile. It was developed in the late 1960s at Lawrence Livermore National Laboratory.-Specifications:The W68 weighs...

 and W76
W76
The W76 is a United States thermonuclear warhead. It was manufactured from 1978-1987, and is still in service .The W-76 is carried inside a Mk-4 re-entry vehicle. U.S...

 nuclear warheads, is a mixture of 80% PETN and 20% of Sylgard 182, a silicone rubber
Silicone rubber
Silicone rubber is an elastomer composed of silicone—itself a polymer—containing silicon together with carbon, hydrogen, and oxygen. Silicone rubbers are widely used in industry, and there are multiple formulations...

. It is often phlegmatized
Phlegmatized
Phlegmatized is a term applied to an explosive that has had an agent added to stabilize or desensitize it. Sometimes this is desirable, to enable handling or to reduce the rate of combustion. Typical phlegmatizing agents include wax, paper, water, and paraffin. These agents are nearly always...

 by addition of 5–40% of wax
Wax
thumb|right|[[Cetyl palmitate]], a typical wax ester.Wax refers to a class of chemical compounds that are plastic near ambient temperatures. Characteristically, they melt above 45 °C to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents...

, or by polymers (producing polymer-bonded explosive
Polymer-bonded explosive
A polymer-bonded explosive, also called PBX or plastic-bonded explosive, is an explosive material in which explosive powder is bound together in a matrix using small quantities of a synthetic polymer...

s); in this form it is used in some cannon shells up to 30 mm caliber
30 mm caliber
30 mm caliber ammunition is usually used in autocannon. Such ammunition includes NATO standard 30 × 173 mm and 30 × 113 mm and Soviet 30 × 165 mm ammunition widely used around the world....

, though unsuitable for higher calibers. It is also used as a component of some gun propellant
Propellant
A propellant is a material that produces pressurized gas that:* can be directed through a nozzle, thereby producing thrust ;...

s and solid rocket propellants. Nonphlegmatized PETN is stored and handled with approximately 10% water content. PETN alone cannot be cast
Casting
In metalworking, casting involves pouring liquid metal into a mold, which contains a hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process...

 as it explosively decomposes slightly above its melting point, but it can be mixed with other explosives to form castable mixtures.

PETN can be initiated by a laser
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...

. A pulse with duration of 25 nanoseconds and 0.5–4.2 joules of energy from a Q-switched ruby laser
Ruby laser
A ruby laser is a solid-state laser that uses a synthetic ruby crystal as its gain medium. The first working laser was a ruby laser made by Theodore H. "Ted" Maiman at Hughes Research Laboratories on May 16, 1960....

 can initiate detonation of a PETN surface coated with a 100 nm thick aluminium layer in less than half microsecond.

PETN has been replaced in many applications by RDX
RDX
RDX, an initialism for Research Department Explosive, is an explosive nitroamine widely used in military and industrial applications. It was developed as an explosive which was more powerful than TNT, and it saw wide use in WWII. RDX is also known as cyclonite, hexogen , and T4...

, which is thermally more stable and has longer shelf life
Shelf life
Shelf life is the length of time that food, drink, medicine, chemicals, and many other perishable items are given before they are considered unsuitable for sale, use, or consumption...

. PETN can be used in some ram accelerator
Ram accelerator
A ram accelerator has the same function as a gun; i.e., it is a device for accelerating projectiles; however, it is entirely different in that jet-engine-like propulsion cycles utilizing ramjet and/or scramjet combustion processes are used to accelerate a projectile to extremely high speeds...

 types. Replacement of the central carbon atom with silicon
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...

 produces Si-PETN, which is extremely sensitive.

Terrorist use

In 1983, the "Maison de France" house in Berlin was brought to a near-total collapse by the detonation of 24 kilograms (52.9 lb) of PETN by terrorist Johannes Weinrich
Johannes Weinrich
Johannes Weinrich is a German left-wing political militant. Weinrich was a founder of the Revolutionary Cells and later became a close aide to Carlos the Jackal...

.

In December 2001, al-Qaeda
Al-Qaeda
Al-Qaeda is a global broad-based militant Islamist terrorist organization founded by Osama bin Laden sometime between August 1988 and late 1989. It operates as a network comprising both a multinational, stateless army and a radical Sunni Muslim movement calling for global Jihad...

 member Richard Reid
Richard Reid (shoe bomber)
Richard Colvin Reid , also known as the Shoe Bomber, is a self-admitted member of al-Qaeda who pled guilty in 2002 in U.S. federal court to eight criminal counts of terrorism stemming from his attempt to destroy a commercial aircraft in-flight by detonating explosives hidden in his shoes...

, the "Shoe Bomber", used PETN in the sole of his sneaker in his unsuccessful attempt to blow up American Airlines Flight 63
American Airlines Flight 63
The 2001 shoe bomb plot was a failed bombing attempt that occurred on American Airlines Flight 63 flying from Charles De Gaulle International Airport in Paris, France, to Miami International Airport in Miami, Florida, on December 22, 2001.-Incident:...

 from Paris to Miami. He had intended to use the solid triacetone triperoxide (TATP) as a detonator.

In August 2009, PETN was used in an attempt by al-Qaeda in the Arabian Peninsula
Al-Qaeda in the Arabian Peninsula
Al-Qaeda in the Arabian Peninsula is a militant Islamist organization, primarily active in Yemen and Saudi Arabia. It was named for al-Qaeda, and says it is subordinate to that group and its now-deceased leader Osama bin Laden, a Saudi citizen whose father was born in Yemen...

 to murder the Saudi Arabian Deputy Minister of Interior Prince Muhammad bin Nayef
Muhammad bin Nayef
Prince Mohammad bin Naif bin Abdul Aziz Al-Saud is the Saudi Deputy Interior Minister in charge of Counter-Terrorism. He survived an assassination attempt in August 2009.-Personal life:Born in Jeddah, he moved to Riyadh...

, by Saudi suicide bomber Abdullah Hassan al Asiri
Abdullah Hassan Al Aseery
Abdullah Hassan al-Asiri was a Saudi Arabian member of al Qaeda. His name is an ascription to the 'Asir Province of Saudi Arabia...

. The target survived and the bomber died in the blast. The PETN was hidden in the bomber's rectum
Rectum
The rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...

, which security experts described as a novel technique.

On December 25, 2009, PETN was found in the underwear of Umar Farouk Abdulmutallab
Umar Farouk Abdulmutallab
Umar Farouk Abdulmutallab , popularly referred to as the "Underwear Bomber", is a suspected terrorist who attempted to detonate plastic explosives hidden in his underwear while on board Northwest Airlines Flight 253, en route from Amsterdam to Detroit, Michigan, on December 25,...

, the "Christmas Day bomber", a Nigerian with links to al-Qaeda in the Arabian Peninsula.
According to U.S. law enforcement officials, he had attempted to blow up Northwest Airlines Flight 253
Northwest Airlines Flight 253
Northwest Airlines Flight 253 was an international passenger flight from Amsterdam Airport Schiphol in Haarlemmermeer, Netherlands, to Detroit Metropolitan Wayne County Airport in Romulus, Michigan, United States...

 while approaching Detroit from Amsterdam. Abdulmutallab had tried, unsuccessfully, to detonate approximately 80 grams (2.8 ounces) of PETN sewn into his underwear by adding liquid from a syringe; however, only a small fire resulted.

In the al-Qaeda in the Arabian Peninsula October 2010 cargo plane bomb plot, two PETN-filled printer cartridges were found at East Midlands Airport and in Dubai
Dubai
Dubai is a city and emirate in the United Arab Emirates . The emirate is located south of the Persian Gulf on the Arabian Peninsula and has the largest population with the second-largest land territory by area of all the emirates, after Abu Dhabi...

 on flights bound for the U.S. on an intelligence tip. Both packages contained sophisticated bombs concealed in computer printer cartridges filled with PETN. The bomb found in England contained 400 grams (14.1 oz) of PETN, and the one found in Dubai contained 300 grams (10.6 oz) of PETN. Hans Michels, professor of safety engineering
Safety engineering
Safety engineering is an applied science strongly related to systems engineering / industrial engineering and the subset System Safety Engineering...

 at University College London
University College London
University College London is a public research university located in London, United Kingdom and the oldest and largest constituent college of the federal University of London...

, told a newspaper that 6 grams (0.2 oz) of PETN "— around 50 times less than was used – would be enough to blast a hole in a metal plate twice the thickness of an aircraft's skin." In contrast, according to an experiment conducted by a BBC documentary team designed to simulate Abdulmutallab's Christmas Day bombing, using a Boeing 747 airplane, even 80 grams of PETN was not sufficient to materially damage the airplane's fuselage.

PETN was also used in recent New Delhi high court bomb blast case in Indian Mujahedeen

Detection

In the wake of terrorist PETN bomb plots, an article in Scientific American
Scientific American
Scientific American is a popular science magazine. It is notable for its long history of presenting science monthly to an educated but not necessarily scientific public, through its careful attention to the clarity of its text as well as the quality of its specially commissioned color graphics...

noted that even if all cargo were screened, PETN is difficult to detect because it has a very low vapor pressure
Vapor pressure
Vapor pressure or equilibrium vapor pressure is the pressure of a vapor in thermodynamic equilibrium with its condensed phases in a closed system. All liquids have a tendency to evaporate, and some solids can sublimate into a gaseous form...

 at room temperature, meaning very little of it gets into the air around the bomb, where it can be detected. The Los Angeles Times noted in November 2010 that because of its more stable molecules, and lower vapor, it is more difficult to detect by bomb-sniffing dogs and the trace swabs then used by the U.S. Transportation Security Administration
Transportation Security Administration
The Transportation Security Administration is an agency of the U.S. Department of Homeland Security that exercises authority over the safety and security of the traveling public in the United States....

.

Many technologies can be used to detect PETN, a number of which have been implemented in public screening applications, primarily for air travel. PETN is just one of a number of explosive chemicals typically of interest in that area, and it belongs to a family of common nitrate-based explosive chemicals
Nitro compound
Nitro compounds are organic compounds that contain one or more nitro functional groups . They are often highly explosive, especially when the compound contains more than one nitro group and is impure. The nitro group is one of the most common explosophores used globally...

 which can often be detected by the same tests.

One technology, detectors that test swabs wiped on passengers and their baggage for traces of explosives, is generally reserved for travelers who are thought to merit additional scrutiny. A second type of machine, whole-body imaging scanners, use radio-frequency electromagnetic waves, low-intensity X-rays or T-rays of terahertz frequency to detect objects under clothing; these devices were of limited availability because of cost, privacy groups' opposition and industry concerns about bottlenecks.

Both parcels in the 2010 cargo plane bomb plot were x-rayed without the bombs being spotted. Qatar Airways
Qatar Airways
Qatar Airways Company Q.C.S.C. , operating as Qatar Airways, is the flag carrier of Qatar. Headquartered in the Qatar Airways Tower in Doha, it operates a hub-and-spoke network, linking over 100 international destinations from its base in Doha, using a fleet of over 100 aircraft...

 said the PETN bomb "could not be detected by x-ray screening or trained sniffer dogs". The Bundeskriminalamt
Federal Criminal Police Office (Germany)
The Federal Criminal Police Office of Germany is a national investigative police agency in Germany and falls directly under the Federal Ministry of the Interior...

 received copies of the Dubai x-rays, and an investigator said German staff would not have identified the bomb either. New airport security procedures followed in the U.S., largely to protect against PETN.

Medical use

Like nitroglycerin (glyceryl trinitrate) and other nitrates, PETN is also used medically as a vasodilator in the treatment of heart conditions
Heart disease
Heart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...

. These drugs work by releasing the signaling gas nitric oxide
Nitric oxide
Nitric oxide, also known as nitrogen monoxide, is a diatomic molecule with chemical formula NO. It is a free radical and is an important intermediate in the chemical industry...

 in the body. The heart medicine Lentonitrat is nearly pure PETN.

Monitoring of oral usage of the drug by patients has been performed by determination of plasma levels of several of its hydrolysis products, pentaerythritol dinitrate, pentaerythritol mononitrate and pentaerythritol, in plasma using gas chromatography-mass spectrometry
Gas chromatography-mass spectrometry
Gas chromatography–mass spectrometry is a method that combines the features of gas-liquid chromatography and mass spectrometry to identify different substances within a test sample. Applications of GC-MS include drug detection, fire investigation, environmental analysis, explosives investigation,...

.

Further reading

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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