Radiation-induced pyrolysis of solid fuels for ramjet application

A wide variety of hydroxyl-terminated polybutadiene (HTPB) based fuels are experimentally assessed in anaerobic reaction. In this study HTPB pyrolysis is investigated using a CO2 laser as the energy source. The formulation of the solid fuel samples is systematically changed to isolate the effects of carbon black, metal fuel additives, and small amounts of oxidizer. In addition, chemical changes to the fuels including curative type and base polymer are varied. Rates of pyrolysis reaction are reported for a wide range of solid fuels applicable to ramjet application. Processes involving the sintering together of metal particles, accumulation of carbon black, and formation of a melt layer are found to affect the reaction rate. It is determined that the surface composition is the most influential factor influencing the regression rate of HTPB based fuels.