RDX-based explosives

A kit for detecting explosives on suspects hands or clothing — Explosives Handling Detection Kit — was developed by Newhouser and Dougherty in 1972 [96]. It was designed to detect three types of explosives, defined by the authors as TNT-based explosives, RDX-based explosives, and NG-... 

The gas-enhanced bombs described here are even more destructive. Terrorists used bombs of this type in their attacks on the U.S. embassy and the marine barracks in Beirut in 1983. Explosives experts initially attributed the marine bombing to about 12,000 pounds of TNT, judging from the tremendous damage caused by the explosion. Israeli intelligence experts now believe the bombs were composed of about 600 pounds of an RDX-based explosive and a propane booster. They also believe that die bombs were prepared by East German advisors working with Syrian terrorists because production of FAE is relatively specialized and not widely known. 

Figure 12.3 HMX- and RDX-based explosives [9]. (Source http / / www.army-technology.com/contractors/explosives/ dyno/dyno2.html.)...

Marinkas, A., C. Hu, andC. Smith. 1998. Use of recycled RDX for production of RDX-based explosives. Proceedings of 4th Life Cycles of Energetic Materials Conference, Fullerton, CaUf., March 29-April 1. 

Cyclic nitramines such as RDX or cyclotetra-methylenetetranitramine (HMX) are widely used in military composites such as Composition B (TNT and RDX) and Composition C-4 (US) or PE-4 (British) and in commercial blasting explosives such as Semtex (a Czech-made mining explosive). HMX is present as a by-product in RDX made by the Bach-mann process and has applications in explosives to be used in high-temperature environments. Chemical tests for RDX include the J-Acid and thymol tests. A number of TLC systems for RDX and HMX have been reported. With adequate sample, IR identification of the pure material in a micro-potassium bromide pellet is simple. If a diamond anvil sample holder or microscope attachment is available, excellent spectra of pure samples of milligram size or even of single crystals are easily obtained. When HMX is observed in RDX-based explosives, its concentration may suggest the national origin of the explosive. 

Mixtures of TNT, RDX, and/or AN are used as TNT-based explosives. Various additives such as aluminum powder, barium nitrate, and/or some other small amounts of materials are used. Densities are in the range 1450-1810 kg m"l Aluminum powder is added to obtain bubble energy when used in underwater conditions. 

Though the theoretical detonation velocity and pressure at the CJ point are expressed by very simplified expressions, the computed results obtained by means of Eq. (9.7) are confirmed by measured data for RDX- and TNT-based explosives, as shown in Table 9.110 (Cp-B indicates Composition B , with the two columns relating to different particle sizes). 

CL-20 was evaluated in both propellant and explosive formulations. A large number of CL-20-based PBXs are reported in the literature. A comparison of their VOD with that of the corresponding HMX-based formulations reveals a 12-15% higher energy potential of CL-20-based formulations. CL-20 is also a superior alternative to RDX and HMX for application in low-signature rocket propellants. CL-20-based propellants offer burn-rates much higher (-35-110%) than those of HMX-based propellants. The performance of CL-20-based propellants in terms of Isp is found to be higher than those of RDX-based propellants. 

SX-2. Brit-made RDX-based sheet expl Ref F.B. Wells, Some Properties of the British Flexible Explosive SX-2 , PATR 4782 (1975) (limited distribution)... 

Interfacing the TEA to both a gas and a HPLC has been shown to be selective to nitro-based explosives (NG, PETN, EGDN, 2,4-DNT, TNT, RDX and HMX) determined in real world samples, such as pieces of explosives, post-blast debris, post-blast air samples, hand swabs and human blood, at picogram level sensitivity [14], The minimum detectable amount for most explosives reported was 4-5 pg injected into column. A pyrolyser temperature of 550°C for HPLC-TEA and 900°C for GC/TEA was selected. As the authors pointed out, GC uses differences in vapour pressure and solubility in the liquid phase of the column to separate compounds, whereas in HPLC polarity, physical size and shape characteristics determine the chromatographic selectivity. So, the authors reported that the use of parallel HPLC-TEA and GC-TEA techniques provides a novel self-confirmatory capability, and because of the selectivity of the technique, there was no need for sample clean-up before analysis. The detector proved to be linear over six orders of magnitude. In the determination of explosives dissolved in acetone and diluted in methanol to obtain a 10-ppm (weight/volume) solution, the authors reported that no extraneous peaks were observed even when the samples were not previously cleaned up. Neither were they observed in the analysis of post-blast debris. Controlled experiments with handswabs spiked with known amounts of explosives indicated a lower detection limit of about 10 pg injected into column. 

PBX), which are based on a binder and a crystalline explosive such as RDX. Secondary explosives also can be classified according to their chemical structure as nitroaromatics, which include TNT, and nitramines, which include RDX. 

Because of its higher density, HMX has replaced RDX in explosive applications for which energy and volume are important. It is used in castable TNT-based binary explosives, as the main ingredient in high-performance plastic-bonded explosives, and in high-performance solid propellants. 

The Fido sensor is an extremely sensitive and selective detector for nitroaromatic explosives such as TNT. The sensor has also been shown to detect most smokeless powders and black powders. Work is now underway to develop polymers that enable detection of nitramine explosives, such as RDX and HMX. Recently, a new polymer was tested that shows promise for detection of the taggant dimethyldinitro butane (DMNB). Development of polymers for detection of peroxide-based explosives is also planned. 

Despite of the fact that several explosives as military grade RDX, other RDX-based materials, such as C4, Urea Nitrate (UN) and especially Semtex generate strong emissions (Fig. 7.5), they are not characteristic enough to use them for their identification emissions on the background of naturally occurring objects. The similar conclusion, that luminescence properties provide httle hope for the use of UV-excited fluorescence as a technique to perform safe standoff detection of adsorbed explosive particulates under real-world conditions with a useful degree of reliability was reached by Phifer et al. (2006). 

Acid—Base Chemistry. Acetic acid dissociates in water, pK = 4.76 at 25°C. It is a mild acid which can be used for analysis of bases too weak to detect in water (26). It readily neutralizes the ordinary hydroxides of the alkaU metals and the alkaline earths to form the corresponding acetates. When the cmde material pyroligneous acid is neutralized with limestone or magnesia the commercial acetate of lime or acetate of magnesia is obtained (7). Acetic acid accepts protons only from the strongest acids such as nitric acid and sulfuric acid. Other acids exhibit very powerful, superacid properties in acetic acid solutions and are thus useful catalysts for esterifications of olefins and alcohols (27). Nitrations conducted in acetic acid solvent are effected because of the formation of the nitronium ion, NO Hexamethylenetetramine [100-97-0] may be nitrated in acetic acid solvent to yield the explosive cycl o trim ethyl en etrin itram in e [121 -82-4] also known as cyclonit or RDX. 

Tetiyl. 2,4,6-Trinitrophenylmethylm tramine (tetryl) was used ia pressed form, mostly as a booster explosive and as a base charge ia detonators and blasting caps because of its sensitivity to initiation by primary explosives and its relatively high energy content. Properties are presented ia Table 11 (173). Batch and continuous processes for the production of tetryl have been developed. Tetryl is no longer used ia the United States and has been replaced by RDX (174-178). 

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