Experimental and Simulative Thermal Stability Study of HTPE Solid Propellants in Different Scales

The hydroxyl-terminated polyether (HTPE) solid propellants are widely recognized as promising alternatives for hydroxyl-terminated polybutadiene (HTPB) propellants due to their compliance with insensitive munition characteristics of composite solid propellant. This study reports thermal stability investigation of HTPE solid propellants in different scales with the help of differential scanning calorimetry (DSC, 0.9 mg), accelerating rate calorimetry (ARC, 0.219 g), and slow cookoff (112 g) tests by taking HTPE/A3/Al/AP/PSAN composite solid propellant as an example. More importantly, for the first time, thermal decomposition kinetic parameters of HTPE solid propellant were calculated by employing iso-conversional Friedman method and using DSC experimental data at different heating rates. The simulation results of adiabatic combustion and slow cook-off of the HTPE propellant were obtained by applying the kinetic parameters in Advanced Kinetics and Technology Solutions software, which exhibited satisfied consistency with the experimental results, with less than 2% average deviation. Finally, the validated kinetic parameters were further employed to describe the large-scale thermal hazards of HTPE propellant and the predicted self-accelerating decomposition temperature of HTPE propellant in 50 kg-scale was 94.2 degrees C. Our simulative study provided a cogent and convenient strategy to understand thermal hazard of HTPE solid propellant in different scales during usage, storage, and transportation.