Role of Thermochemical Decomposition in Energetic Material Initiation Sensitivity

Catastrophic initiation of an energetic material consists of a complex, interactive, sequential train of mechanistic mechanical, physical, and chemical processes which occur over a finite time period and proceed from macroscopic into sub-microscopic composition levels (bulk > crystalline > molecular > atomic). Initiation results when these processes proceed at a rate which generates sufficient energy (heat) to reach a threshold stage within this finite time period. Thus, the rate at which these mechanistic processes occur defines initiation sensitivity and affects performance. Thermochemical decomposition processes regulate the rate at which heat energy is released at the molecular level, and therefore to some extent, control energetic material initiation sensitivity and performance characteristics. Kinetic deuterium isotope effect (KDIE) data, obtained during the ambient pressure thermochemical decomposition process, identifies the mechanistic ratecontrolling bond rupture which ultimately regulates the energy release rate of a given energetic material. This same rate-controlling bond rupture also appears as a significant rate-limiting feature in higher order deflagration, combustion, and explosion phenomena. The effect the KDIE-determined rate-controlling bond rupture exerts on initiation sensitivity, and its potential influence in combustion and explosion performance is delineated.