Thermal Decomposition Reaction Kinetics of a HAN-based Gel Propellant

In order to study the thermal decomposition characteristics of hydroxylamine nitrate (HAN) based gel propellant, the thermal decomposition of two kinds of HAN-based gel propellant samples containing polyvinyl alcohol (PVA) with different mass was tested by differential scanning calorimeter (DSC) and thermogravimetric analyzer (TGA). A double-base propellant was chosen to be compared with this propellant. The thermal decomposition process of HAN-based gel propellant and double-base propellant was analyzed and kinetic parameters of their thermal decomposition reaction were obtained. Activation energy was calculated by an isoconversional method. The critical temperature of thermal explosion and self accelerating decomposition temperature were calculated by Zhang-Hu-Xie-Li method. Malek method is used to infer the most probable mechanism function of thermal decomposition reaction. Results show that the thermal decomposition of HAN-based gel propellant is a continuous exothermic process and has a small amount of residue. The activation energy is about 100 kJ/mol. The critical temperature of thermal explosion and self accelerating decomposition temperature increase when the content of PVA increases. HAN-based gel propellant has good thermal stability compared with thermal decomposition parameters of double-base propellant.