Synthetic Functionalization and Reaction Kinetics of Pentaerythritol Tetranitrate (PETN) Derivatives

The handling sensitivity of explosives is influenced by a number of fundamental chemical properties, with contributions from both kinetics (reaction rates) and thermodynamics (heat of explosion). In order to evaluate the interplay of these parameters, we have designed a series of derivatives of pentaerythritol tetranitrate (PETN) by substituting nitrate ester functional groups with inert hydroxy groups. The four explosives have similar chemical properties but exhibit wildly different handling sensitivities when tested for sub-shock sensitivity using the drop-weight impact test. The thermal stability of each PETN derivative has been evaluated via its reaction kinetics using molecular dynamics simulations to determine time to explosion or trigger linkage rupture for each derivative over a range of temperatures. In general, it is expected that the first energetic bond to break (i.e. the "trigger linkage") is critical in influencing the sensitivity of an explosive. Our preliminary results suggest while all four explosives have the same trigger linkages – the nitrate ester – the relatively small specific heats of explosion of the mono-nitrate and di-nitrate derivatives result in lower impact sensitivity values. Ongoing experiments with more advanced diagnostics will also be discussed.