Tuning Physical and Chemicalproperties of explosives through Synthetic Modifications

When handling explosives one of the most important factors to consider is the sensitivity of the material towards common stimuli such as impact, friction, electrostatic discharge and temperature. Explosive handling sensitivity is dictated by numerous molecular and physical properties Chemical effects such as thermodynamics, decomposition pathways and bond dissociation energies correlate with handling sensitivity. In addition it is possible that macroscale factors such as crystal structure, crystal packing, hydrogen bonding and electrostatic effects can also play a role in a materials handling sensitivity. Understanding how these molecular properties influence explosive safety is key to developing a blueprint for designing energetics with specific properties and sensitivities. We have been making selective modifications to specific molecular backbones in order to control properties without changing the entire molecule. Specifically, we have focused on the handling sensitivity of three molecular systems: (1) the explosive erythritol tetranitrate (ETN) in both the solid and liquid state, (2) stereochemical isomers, sorbitol hexanitrate and mannitol hexanitrate, which have distinct physical properties such as crystal packing and melting point, and lastly (3) a modified erythritol molecular backbone with systematically varied energetic functional groups. Results from these studies have shown that physical characteristics such as material phase and melting point play large roles in explosive sensitivity. Additionally these studies have demonstrated that through selective modification, explosive sensitivity can be tuned though manipulation of various explosive functional groups.