THERMAL DEGRADATION AND KINETIC PARAMETER OF TWO INSENSITIVE PROPELLANTS: AN EXPERIMENTAL STUDY

Low vulnerability gun propellants are energetic materials designed to resist unintended ignition stimuli. The present work aims to determine kinetic parameters for two insensitive powders. The first propellant is made of 1,3,5-trinitro-1,3,5-triazinane, usually called hexogen (RDX), and hydroxyl-terminated polybutadiene as a binder. The second one is a nitrocellulose (NC) based propellant, which also contains diphenylamine. These propellants are commercial products and were provided by ArianeGroup. Both propellants have a cylindrical shape with several perforations. Only a few milligrams of each sample are used in this study. Combustion properties of these samples were already studied and published concerning the RDX- and NC-based propellants. This experimental study focuses on two thermal analysis methods, which are the thermogravimetric analysis (TGA) and the differential scanning calorimetry (DSC). This study is complementary to the previous works on combustion behavior. Data obtained with such thermal analysis techniques provide important results concerning thermal behavior of propellants. These results are useful to study ignition and combustion, but also storage (aging). For each propellant, DSC and TGA analyses are performed using several heating rates to obtain their activation energies. Comparison of their reactivities is done by working under two different gaseous atmospheres (argon and nitrogen). Activation energies obtained using the two techniques and under the two atmospheres are given, discussed, and compared to literature available data.