(541a) On Significance of Thermophysical Properties of Energetic Materials
AIChE Annual Meeting
Thursday, November 12, 2009 - 8:35am to 8:55am
Few energetic materials were used in times of war and peace before the end of the cold war era. However since the end of the cold war era and the current terrorist activities, significant research is taking place in the synthesis, production, and use of such materials. Information on thermophysical properties of energetic materials is essential for:
1. Military needs to minimize the collateral damage to all sites other than the targeted sites,
2. Determining the fate of these chemicals in the environment,
3. Detecting hidden explosives - extremely accurate data on vapor pressure is required for development of sensors,
4. Proper disposal of these hazardous materials,
5. Preventing smuggling of these materials in their original form or as bombs, etc.
6. Testing predictive methods associated with the testing and fielding of new energetic materials to minimize the cost and time associated with an experimental program. For example, prediction of crystal density paves the way in predicting detonation velocities. Enthalpies of formation and sublimation are critical in assessing the potential energy release and performance in a gun or a warhead.
7. Developing models to predict accurately physicochemical properties. The models currently used to predict properties are far from satisfactory.
8. Studying syntheses pathways, reaction mechanisms and products, exhaust plume signature, etc.
9. To develop new energetic materials or improve the existing ones.
10. To improve the sensitivity/insensitivity of the existing energetic materials.
11. To develop energetic compounds for space applications. Specific impulse, ballistic and mechanical properties in addition to hazard and safety factors are important.
One of the important areas in the study of energetic materials is the detonation performance. Detonation performance is described via detonation velocity, pressure and energy, chemical structure and particle size. In assessing the detonation characteristics, the Chapman-Jouguet [C-J] pressure is perhaps the principal parameter. In addition as the detonation process involves a phase change from solid to gaseous/liquid phases which encompasses the thermal and diffusional processes, a number of transport and kinetic parameters are essential to describe the detonation process. This presentation outlines the need for theoretical and empirical methods of prediction of properties directly connected to performance of energetic materials.