Explosives, and related energetic materials such as propellants and pyrotechnics, have a large amount of stored chemical energy that can be released with a suitable initiation event. The rapid release is facilitated by the proximity of fuel and oxidizer within the molecule. However, the vast majority of compounds used as explosives are under-oxidized, which decreases their performance. New research on microporous coordination polymers from the University of Michigan shows great promise for creating intimately mixed materials with optimized oxygen balances through rationale design. These materials are suitable for use as high performance primary explosives, which are used in small amounts to trigger larger explosives. Lead azide has been the most widely used primary explosive but replacements are needed because of its environmental toxicity and impending regulatory changes to ban the material.
High performance due to molecular scale mixing and optimal oxygen balance
By starting with fuel-rich microporous coordination polymers and controllably introducing an appropriate amount of oxygen-rich guest molecules that adsorb to the nanostructured porous scaffold, University of Michigan researchers have developed highly energetic materials with an optimized oxygen balance. The intimate and balanced mixing with the oxidant results in a hybrid material from two much less energetic materials that releases significantly more energy as measured by differential scanning calorimetry. Sensitivity measurements show that detonation can be triggered with forces comparable to those required for lead azide detonation. This technology is well-suited for use as a primary explosive in blasting caps for mining and military applications.
* High performance primary explosive suitable for mining or military applications
* Environmentally friendly replacement for lead azide and other lead explosives with no loss in performance
* Molecular-level mixing between fuel and oxidant
* Desirable oxygen balance
* Appropriate impact sensitivity for use as a primary explosive
* Generalizable methodology for optimizing performance of a variety of host-guest polymer complexes