Chemicals with explosive properties

The Mond index was developed from the Dow F El by personnel at the ICI Mond division. The third edition of the Dow index, Dow (1973), was extended to cover a wider range of process and storage installations, the processing of chemicals with explosive properties, and the evaluation of a toxicity hazards index. Also included was... 

TABLE 5.3.3.1 Reactive Laboratory Chemicals with Explosive Properties ... 

Pentaerythritol tetranitrate (PETN) (3) is a powerful explosive which exhibits considerable brisance on detonation (VOD 8310 m/s at = 1.77 g/cm ). It is the most stable and least reactive of the common nitrate ester explosives. The relatively high sensitivity of PETN to friction and impact means that it is usually desensitized with phlegmatizers like wax and the product is used in detonation cord, boosters and as a base charge in detonators. Pentaerythritol tetranitrate can be mixed with synthetic polymers to form plastic bonded explosives (PBXs) like detasheet and Semtex-IA. A cast mixture of PETN and TNT in equal proportions is known as pentolite and has seen wide use as a military explosive and in booster charges. The physical, chemical and explosive properties of PETN commend its use as a high explosive. 

Nitro-l,2,4-triazol-5-one (NTO) [Structure (2.49)] or oxynitrotriazole (ONTA)has been reported as another IHE coupled with better performance [152-157]. Almost all aspects of NTO-synthesis, structural aspects, chemical and explosive properties including thermal behavior have been investigated [158-161]. NTO exists in two polymorphic forms, that is, -form and P-form. It has been established that a-NTO is the stable and dominating form whereas P-NTO is only found in the product on recrystallization of NTO from a methanol or ethanol/methylene chloride mixture [162]. French researchers have recently reported its evaluation as an explosive for warhead filling without a binder and also as a PBX [155]. Further, synthesis of NTO is easy consisting of only two steps (Scheme 2.9) and uses inexpensive starting materials. 

There are many published works that seek to predict the explosive properties of chemicals. Some of these are useful but there are almost always exceptions in their predictive powers—thus, none are fully predictive. Probably the most widely known method used to predict or identify compounds or reaction mixtures with explosive properties is called oxygen balance. The potential to be explosive increases as a compound s composition approaches a zero oxygen balance. This means that when the stoichiometric composition of a compound is such that it provides all of the oxygen needed to oxidize all of the other elements to their preferred state, then it has a zero oxygen balance. 

Reactive chemicals, including those with explosive properties, are often important tools for chemical research. Most of these chemicals can be used safely if you are armed with the knowledge and skill and have clear plans to handle these in your laboratory. 

S. F. Vasilevsky and E. V. Tetryakov (Novosibirsk, Russia), together with J. Elguero (Madrid, Spain), have summarized the synthesis, chemical and spectroscopic properties, and biological activity of acetylenic derivatives of pyrazoles, a field which has shown explosive growth in the past few years. 

Chemical and hydrocarbon plant losses resulting from fires and explosions are substantial, with yearly property losses in the United States estimated at almost 300 million (1997 dollars).1 Additional losses in life and business interruptions are also substantial. To prevent accidents resulting from fires and explosions, engineers must be familiar with... 

The OSHA PSM Standard lists 131 distinct chemicals with toxic or reactive properties.40 It includes 25 chemicals with an NFPA rating of 3 and 13 chemicals with an NFPA rating of 4. PSM applies to processes that involve listed chemicals at or above threshold quantities and to processes with flammable liquids or gases onsite in one location, in quantities of 10,000 pounds or more. Companies that manufacture explosives and pyrotechnics are also required to comply with the standard. 

Detonation (and Explosion), Stability of Explosives. Andreev 8t Belyaev (Ref 1, p 106) stated that stability, of explosive (stoykost vzryvchatogo veshchestva) is determined by the rate of changes in its physical and chemical (and consequently of explosive) properties with duration of time. The smaller the rate, the more stable is explosive and vice versa... 

The principal feature of this relationship is that F values are derived solely from molecular formulae and chemical structures and require no prior knowledge of any physical, chemical or thermochemical properties other than the physical state of the explosive that is, explosive is a solid or a liquid [72]. Another parameter related to the molecular formulae of explosives is OB which has been used in some predictive schemes related to detonation velocity similar to the prediction of bri-sance, power and sensitivity of explosives [35, 73, 74]. Since OB is connected with both, energy available and potential end products, it is expected that detonation velocity is a function of OB. As a result of an exhaustive study, Martin etal. established a general relation that VOD increases as OB approaches to zero. The values of VOD calculated with the use of these equations for some explosives are given in the literature [75] and deviations between the calculated and experimental values are in the range of 0.46-4.0%. 

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