Burning and radiance properties of Si in AP/HTPB based compositions

Abstract

Silicon (Si) has high caloric power and its combustion product silica (SiO2) shows high emissivity in the far infrared (8–14 μm). The study adds different contents of Si into the Ammonium Perchlorate/Hydroxyl-terminated polybutadiene (AP/HTPB) based compositions, aiming to investigare the influence of Si on the burning and radiance properties of AP/HTPB based compositions by using a FTIR remote-sensing spectrometer, a Fourier Transform Infrared Spectrometer, a far-infrared thermal imager and a synchronous thermal analysis instrument. The experimental results show that the combustion oxidation reaction of Si is restricted by the oxygen balance of the system. When the oxygen balance exceeds 25 (Si content is greater than 15%), the insufficient oxygen supply makes the combustion rate significantly reduced from 0.52 g/s to 0.36 g/s, and Si cannot be closely related to the infrared performance and combustion of the AP/HTPB agent. When the Si content is less than 15%, the infrared radiation energy of the entire infrared band of AP/HTPB can be increased, and as the Si content increases, the radiation temperature increases rapidly from 342 °C to 1070 °C, and the far-infrared radiation intensity increases from 1.56 W/Sr to 7.81 W/Sr. The smallest mid-to-far infrared radiation ratio of 3 can be obtained when the Si content is 15%. Therefore, Si has a positive effect on improving the infrared radiation performance of AP/HTPB.