Compatibility of HMX and Lecithin through Multiple Thermal Analyses

Thermal compatibility of energetic materials and formulation ingredients is typically determined through interpretation of one or more thermochemical analyses, including dynamic and/or isothermal differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). For example, two materials may be deemed “incompatible” if the energetic decomposition exotherm temperature shifts to a 20-degree lower temperature upon contact with a particular formulation candidate material. The rationale behind the “incompatible” designation is that a shift in the exotherm temperature indicates some amount of inter- reaction between the two materials. However, it is unclear from this single test whether this incompatibility would cause deleterious real-world effects, either in an accident or long-term storage scenario, without understanding the decomposition kinetics. Here, we investigate an apparent incompatibility of HMX and lecithin, an emulsifier, through multiple thermal analyses, including dynamic and isothermal kinetics by DSC in addition to DSC, TGA, and vacuum thermal stability (VTS).

DISTRIBUTION STATEMENT A (25-010). Approved for public release. Distribution is unlimited.