Detonation, energetic materials

High-pressure experiments promise to provide insight into chemical reactivity under extreme conditions. For instance, chemical equilibrium analysis of shocked hydrocarbons predicts the formation of condensed carbon and molecular hydrogen.17 Similar mechanisms are at play when detonating energetic materials form condensed carbon.10 Diamond anvil cell experiments have been used to determine the equation of state of methanol under high pressures.18 We can then use a thermodynamic model to estimate the amount of methanol formed under detonation conditions.19... 

Keywords Detonation Energetic materials Electric spark Impact Shock ... 

Lewis, B. und Elbe, G. von Combustion, Flames and Explosives of Gases, 3. Aufl., Academic Press, Orlando, Florida 1987 Energetic Materials New Synthesis Routes, Ignition, Propagation and Stability of Detonation, Hrsg. Field, J.E. und Gray, R, The Royal Society, London 1992... 

Decomposition, Combustion, and Detonation Chemistry of Energetic Materials, Hrsg. Brill, T.B., Russel, RB., Tao, W.C., Wardle, R.B., Materials Research Society (MRS), Pittburgh, PA, USA, 1996 (Symposium Series Vol. 418)... 

Thermodynamic cycles are a useful way to understand energy release mechanisms. Detonation can be thought of as a cycle that transforms the unreacted explosive into stable product molecules at the Chapman-Jouguet (C-J) state,15 which is simply described as the slowest steady-state shock state that conserves mass, momentum, and energy (see Figure 1). Similarly, the deflagration of a propellant converts the unreacted material into product molecules at constant enthalpy and pressure. The nature of the C-J state and other special thermodynamic states important to energetic materials is determined by the equation of state of the stable detonation products. 

Despite the many successes in the thermochemical modeling of energetic materials, several significant limitations exist. One such limitation is that real systems do not always obtain chemical equilibrium during the relatively short (nanoseconds-microseconds) time scales of detonation. When this occurs, quantities such as the energy of detonation and the detonation velocity are commonly predicted to be 10-20% higher than experiment by a thermochemical calculation. 

A summary of our results on the phase diagram of water is shown in Figure 8. We find that the molecular to non-molecular transition in water occurs in the neighborhood of the estimated ZND state of HMX. This transition shows that the detonation of typical energetic materials occurs in the neighborhood of the molecular to non-molecular transition. 

Detonation Most violent type of explosive event supersonic decomposition reaction that propagates through energetic material to produce an intense shock in the surrounding medium (air or water) and rapid plastic deformation. 

Hybrid compounds containing heterocyclic nitramine and em-dinitro functionality represent a class of high performance energetic materials. Such compounds frequently exhibit higher heats of formation, crystal density, detonation velocity and pressure, and better oxygen balance compared to analogous aromatic compounds. 

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