Ignition and combustion of hydroxyl-terminated polybutadiene (HTPB)-based solid fuels loaded with innovative micrometer-sized metals

This paper discusses experimental investigations on the effects of innovative micrometer-sized metal additives on the ignition and burning of solid fuel formulations based on Hydroxyl-Terminated PolyButadiene (HTPB). Gaseous oxygen was selected as the oxidizer for ignition delay and regression rate tests. A relative grading of solid fuel performance was carried out taking unloaded HTPB as the baseline. Three different micrometer-sized metallic additives were investigated: conventional magnesium (Mg), amorphous aluminum (am_Al,) and magnesium–boron composite (MgB). Ignition delay is highly depending on pressure, while the linear regression rate was not appreciably affected as the pressure increased from 1.0 to 1.9 MPa. All of the micrometer-sized additives have a positive effect on enhancing both linear regression rate and mass burning rate, while amorphous aluminum (am_Al) demonstrated a larger effect than Mg and composite MgB powders.