Thermal analysis of the decomposition of a LOVA gun propellant based on RDX and Nitrocellulose

International audience ; The undesired ignition of ammunitions during their different stages of life can lead to hazardous situations for goods and people. To tackle this, projects of LOw-Vulnerability Ammunitions (LOVA) have been developed. However, this loss of sensitivity can lead to ignition issues. The study of thermal decomposition is essential to reach a better understanding of ignition phenomena. This paper is about the thermal decomposition of a LOVA gun propellant based on RDX and nitrocellulose. Decomposition is studied by ThermoGravimetric Analysis (TGA) between 30 and 300 °C, under argon atmosphere and five heating rates (0.3, 0.5, 0.8, 1.0, 1.2 K/min). A kinetic analysis method, considering ICTAC recommendations, is developed in this paper and applied to TGA results. The latter allows to determine global kinetic parameters (pre-exponential factor, activation energy and reaction model based on the truncated Sestak-Berggren equation) to obtain a decomposition law depending on temperature and extent of conversion. A model with three kinetic steps is obtained. Its integration provides mass loss curves in good agreement with the TGA results.