This article does not cite any sources. (July 2008) (Learn how and when to remove this template message)
PLX, or Picatinny Liquid Explosive, is a liquid binary explosive, a mixture of 95% nitromethane (NM) along with 5% ethylene diamine (EDA) as a sensitizer. Other amine compounds can be used instead of ethylene diamine, such as triethylene tetramine or ethanolamine, but EDA has been found to be most effective. PLX is a fairly powerful high explosive, marginally exceeding the destructive yield of TNT.
PLX, when mixed, is a transparent liquid with a yellowish tint. Both ethylene diamine and nitromethane are very volatile, requiring the contents to be sealed if any storage is intended. Generally, for safety purposes, the contents are transported separately and mixed on site. PLX is known to have a velocity of detonation (VoD) of anywhere between 6,000 and 7,000 m/s, depending on diameter. Although greatly sensitized by the addition of EDA, PLX still requires a powerful blasting cap or a small booster charge to successfully detonate.
Uses and discovery
PLX was invented during World War II by the Picatinny Arsenal in New Jersey. It was originally designed to clear minefields by being spread via plane over the targeted area or poured from a safe distance and detonated by troops on the ground.
This explosive can also be gelled through the addition of nitrocellulose, ETN, or any number of soluble nitrate esters or gelling agents. This allows for powdered metals, such as aluminum or magnesium, to be suspended in the mixture. The metal powders act as fuel, increasing heat and energy output but lowering the brisance and VoD. The result is a more sustained blast wave and a "push and heave" effect, desirable for thermobaric purposes. Trzciński[who?] reports that 200 grams of a mixture of NM with PMMA as gelling agent and AlMg (45:55, mean particle size = 63 microns) as fuel, in a ratio of 67.2/2.8/30 by mass, has a peak overpressure of 120 kPa 2 m[clarification needed] from the (open air) blast site, a 1.65 TNT equivalency in peak pressure, and a 1.62 equivalency in shockwave impulse.
Sensitizing of nitromethane
It is known that the amine groups (nitrogen atom bonded to carbon and or hydrogen exhibiting a valence pair of electrons) are responsible for the sensitization of nitromethane, chemical formula CH3NO2. It is thought that the amine weakens the C-N bond in the nitromethane, resulting in less energy being needed to break the bond, thus detonation.