Kinetics of energetic materials: Investigation of sublimation and decomposition

Explosives are the compounds that store large amount energy because of their chemical structure. Organic explosives undergo the kinetic processes such as sublimation, recrystallization and diffusion in the storage, and decomposition in both the storage and the applications. In the storage, sublimation, recrystallization and diffusion of molecules combine to undergo a new process called coarsening. The coarsening of materials is a complex process driven by both the kinetics and the thermodynamics. These processes cause the reduction of the surface area of the organic explosives; therefore, influence the physical properties of the stored organic explosives. The reduction of surface area of organic explosives reduces the initiation sensitivity. Sublimation properties of molecular crystals of a benchmark organic explosive were evaluated to understand the coarsening mechanism. This investigation showed that coarsening of explosive can be controlled by doping explosive with the homolog compounds of a organic explosive.

The decomposition of explosives is another kinetic process that influences the intended performances of explosives. The initiation of an explosive leads to the subsequent processes such as chemical decomposition and detonation. The decomposition of an explosive to the end products is the first steps to toward the production of a shock front. A rapid release of the gaseous products along with an enormous amount of heat produced through the heat of reaction makes the decomposition of organic explosives difficult to understand. In this part of the investigation, kinetics of the production of the gas components was evaluated using mass spectrometry. The activation energy of the investigated gas components were obtained as a function of extent of reaction.