INFLUENCE OF BURNING RATE INHIBITORS ON THE THERMAL BEHAVIOR AND DECOMPOSITION KINETICS OF AMMONIUM PERCHLORATE

Abstract

The addition of burning rate inhibitors (BRIs) to propellant formulations can be effective in reducing the burning rate of composite solid propellants (CSPs). Ammonium perchlorate (AP) is commonly used as an oxidizer for CSPs and is a major component of propellants. Therefore, it is of great significance to study the thermolysis performance of AP in the presence of BRIs. In this work, differential scanning calorimetry and thermogravimetric analysis were utilized to study the thermolysis of AP. Oxamide (OXA), ammonium sulfate (AS), ammonium oxalate (AO), and carbamide (CA) were selected as the BRIs. The results showed that as the BRI content increased, the endothermic peak remained essentially unchanged. The exothermic peak in the low-temperature decomposition (LTD) stage shifted to a hightemperature field, while the exothermic peak in the high-temperature decomposition (HTD) stage shifted to a low-temperature field. Furthermore, associated kinetic studies showed that the decomposition activation energies of AP with inhibitors during the LTD stage were higher than that of pure AP, proving that the selected BRIs could effectively inhibit the thermolysis of AP. However, during the HTD stage, the values of the activation energies for decomposition gradually increased in the order of AP + AO, AP + OXA, AP + CA, AP, and AP + AS, indicating that only AS had the effect of inhibition at this time.