Formulating polymers that enhance explosives performance

The design of new explosive and propellant formulations, in compliance with insensitive munitions directives, require that performance be increased, while concurrently increasing stability and safety. Additional requirements include higher density, reduced environmental impact, improved mechanical properties, and extended service life. The combination of high explosives (HE) with modest quantities of polymer has delivered a way to desensitize explosive material to external stimuli (impact, friction, spark, heat, shock). The dilution of the HE, however, limits performance of the formulation. Researchers are thus exploring formulations having high energy density as well as robust safety by implementing new energetic polymers that target performance and mechanical properties.

In one recent study, Lawrence Livermore researchers derived and synthesized a novel set of polymers that increased the heat of formation and decreased carbon content compared to a similar class of polymers. As they note in an associated journal paper, “These metrics are encouraging as we seek to develop future materials that have better physical and mechanical properties to compete with commonly utilized energetic polymers.” These materials are intended to explore the design space and bridge the gap between inert and detonable polymers for use in highly energetic formulations.

This research was highlighted on the back cover of a recent issue of the journal Polymer Chemistry.

[T.A. Manes, G.H. Imler, K.T. Sullivan, and E.V. Bukovsky, Evaluating the bis-isoxazole core for energetic heterocyclic-based oligomers, Polym. Chem. 11, 6149–6156 (2020), doi: 10.1039/D0PY00875C.]