Sensitivity of Energetic Materials: Theoretical Relationships to Detonation Performance and Molecular Structure

It
has been known for decades that high performances for explosives
(as characterized by detonation velocity D, detonation
pressure P, or Gurney energy EG) are connected with high impact sensitivities, i.e., low
values of the drop weight impact height h50. This trade-off is theoretically substantiated for the first time.
It stems from the primary role of the amount of chemical energy evolved
per atom for both performance and sensitivity. Under realistic assumptions,
log­(h50) increases linearly with D–4 or equivalently with P–2 or EG–1. This prediction proves consistent
with experimental data for nonaromatic nitro compounds. The occurrence
of different explosophores on the same molecule is suggested as a
factor influencing the performance-sensitivity trade-off. Finally,
it is shown that a large body of data may be explained by the present
approach, which naturally integrates thermodynamic (energy content)
as well as kinetic (activation energies) aspects. This model should
help in designing powerful high energy compounds with acceptable sensitivity.