Study on the effect of potassium compound on the combustion characteristics of HTPB composite solid propellant

To investigate the effect of potassium compound on the combustion characteristics of hydroxyl-terminated polybutadiene (HTPB) composite solid propellants. Potassium compound were added to the HTPB propellants as flame inhibitors at different concentration gradients, and the effects of the potassium compound on the thermal decomposition and combustion characteristics of these propellants were investigated by thermogravimetric differential calorimetric scanning calorimetry (TG-DSC) and laser ignition combustion experiments. The results showed that the effect of potassium compound on the thermal decomposition of the HTPB composite solid propellant predominantly occurred in the AP/HMX decomposition stage, and the potassium compound affected the synergistic decomposition of AP/HMX. The entire process of the HTPB composite solid propellant combustion slowed down with increasing potassium compound content; this was mainly shown by the increase in ignition delay time and longer combustion time. The intensity of the secondary combustion flame decreased, the maximum flame area and image grayness decreased, and the intensity of the maximum emission spectrum of the secondary combustion flame decreased. With the increase in potassium compound content, the spectral intensity of free radicals produced by combustion shows a decreasing intensity with a delayed trend with the change rule of time. Overall, the potassium compound weakened the combustion of the HTPB composite solid propellant.