Energetic materials composite

Explosives. Explosives can be detected usiag either radiation- or vapor-based detection. The aim of both methods is to respond specifically to the properties of the energetic material that distinguish it from harmless material of similar composition. A summary of techniques used is given ia Table 7. These techniques are useful for detecting organic as well as inorganic explosives (see Explosives and propellants). 

Insensitive Energetic Materials - Particles, Crystals, Composites, Eds. Teipel, U., Herrmann, M., (Symposium Proceeding), Fraunhofer IRB Verlag, 2007, Stuttgart, Germany, ISBN 978-3-8167-7328-3 Organic Chemistry of Explosives... 

One of the attractive features of thermodynamic modeling is that it requires very little information regarding the unreacted energetic material elemental composition, density, and heat of formation of the material are the only information needed. As elemental composition is known once the material is specified, only density and heat of formation need to be predicted. 

Nominal Composition of Energetic Materials Used in Chemical Munitions, 22 2-2 Conditions Used in the Commissioning Runs at HAAP, 24 2-3 Test Matrix for the Army Hydrolysis Study at HAAP, 25 2-4 Residual Energetic Material in End-of-Run Hydrolysate Samples, 28... 

Continuous destruction of energetic material (M28 and Composition B) in a 12-kW test unit. 

TABLE 2-1 Nominal Composition of Energetic Materials Used in Chemical Munitions... 

As was the case with Composition B-4, some energetic materials were detected in the offgases during the addition phase, but none of these persisted throughout the run. No energetic materials were found in the offgases during the postaddition reaction phase. 

In the LANL experiments, all of the energetic material was introduced into the vessel at the beginning of the run, when the caustic was still at ambient temperature in the HAAP runs, the caustic was heated to the reaction temperature before the energetic feed was introduced. Therefore, the rate of destruction from the LANL data is not comparable to that from the HAAP data. It appears that the evolution of gas commenced at about 65-70°C for both Composition B-4 in 20 percent caustic and tetrytol in 12 percent caustic. No temperature data were presented for Composition B-4 in 15 percent caustic, and tetrytol appeared to begin generating gas at a somewhat higher temperature ( 80°C) in 20 percent caustic. 

Slurries of energetic materials from two sources are treated in the SILVER II process the explosive in the rocket and projectile burster tubes (which may be either Composition B or tetrytol) and the ground-up M28 propellant grain in the rocket motors. 

M36 and M34 bursters from rockets are placed in COINS without shearing. These bursters require less exposure time for melting and reaction of the Composition B explosive than the tetrytol in projectile bursters. The energetic material in these rocket bursters is fully extracted from the burster metal and plastic hardware during the COINS processing. 

The physicochemical properties of explosives are fundamentally equivalent to those of propellants. Explosives are also made of energetic materials such as nitropolymers and composite materials composed of crystalline particles and polymeric materials. TNT, RDX, and HMX are typical energetic crystalline materials used as explosives. Furthermore, when ammonium nitrate (AN) particles are mixed with an oil, an energetic explosive named ANFO (ammonium nitrate fuel oil) is formed. AN with water is also an explosive, named slurry explosive, used in industrial and civil engineering. A difference between the materials used as explosives and propellants is not readily evident. Propellants can be detonated when they are subjected to excess heat energy or mechanical shock. Explosives can be deflagrated steadily without a detonation wave when they are gently heated without mechanical shock. 

Crystalline particles that produce gaseous oxidizer fragments are used as oxidizer components and hydrocarbon polymers that produce gaseous fuel fragments are used as fuel components. Mixtures of these crystalline particles and hydrocarbon polymers form energetic materials that are termed composite propellants . The oxidizer and fuel components produced at the burning surface of each component mix together to form a stoichiometrically balanced reactive gas in the gas phase. 

Azide polymers such as GAP and BAMO are also used to formulate AP composite propellants in order to give improved specific impulses compared with those of the above-mentioned AP-HTPB propellants. Since azide polymers are energetic materials that burn by themselves, the use of azide polymers as binders of AP particles, with or without aluminum particles, increases the specific impulse compared to those of AP-HTPB propellants. As shown in Fig. 4.15, the maximum of 260 s is obtained at (AP) = 0.80 and is approximately 12 % higher than that of an AP-HTPB propellant because the maximum loading density of AP particles is obtained at about (AP) = 0.86 in the formulation of AP composite propellants. Since the molecular mass of the combustion products. Mg, remains relatively unchanged in the region above (AP) = 0.8, decreases rapidly as (AP) increases. 

Slurry explosives consist of saturated aqueous solutions of ammonium nitrate with sensitizing additives.[i-3] Nitrates such as monomethylamine nitrate, ethylene glycol mononitrate, or ethanolamine mononitrate are used as sensitizers. Aluminum powder is also added as an energetic material. Table 4.15 shows a typical chemical composition of a slurry explosive. It is important that so-called micro-bubbles are present within the explosives in order to facilitate the initial detonation and the ensuing detonation wave. These micro-bubbles are made of glass or polymeric materials. 

HMX and RDX are energetic materials that produce high-temperature combustion products at about 3000 K. If one assumes that the combustion products at high temperature are HjO, Nj, and CO, rather than COj, both nitramines are considered to be stoichiometricaUy balanced materials and no excess oxidizer or fuel fragments are formed. When HMX or RDX particles are mixed with a polymeric hydrocarbon, a nitramine pyrolant is formed. Each nitramine particle is surrounded by the polymer and hence the physical structure is heterogeneous, similar to that of an AP composite pyrolant... 

Perhaps the place to begin in a book about trace chemical sensing of explosives is to define trace and explosive. If trace is defined as a submilligram quantity, then it should be noted that there are no chemicals that are explosive at trace levels. To clarify this point we need to elaborate on what makes a chemical an explosive. An energetic material is defined as one that releases energy upon decomposition. This material could be an explosive, a propellant, a pyrotechnic, or a fruit cocktail. For an energetic material to be an explosive chemical or composition its must be capable of undergoing decomposition with extremely... 

Materials synthesis is a necessary component in the development of advanced technologies for national security and homeland defense. For instance, new composites, nanoscale molecules and compounds, and polymers are needed for tougher, explosion- or puncture-resistant materials that can be employed in buildings, garments, bridges, and other products and structures. Personal protective materials could be enhanced with new chemical adsorbents filter materials, impermeable membranes, artificial sutures, and improved energetic materials for... 

---