Biuret: a Potential Burning Rate Suppressant in Ammonium Chlorate(VII) Based Composite Propellants

Several composite propellant compositions containing various concentrations of biuret, a new burning rate suppressant, were formulated and studied to optimize the concentration of biuret in the composite propellant. Biuret was used here for the first time in a composite propellant as a burning rate suppressant. The theoretical properties of the compositions containing different concentrations of biuret were computed by using the NASA CEC-71 programme and the burning rate performances were evaluated. In addition, the sensitivity, thermal and mechanical properties of the compositions were also evaluated. The composition containing ammonium chlorate(VII) (AP) 65%, Al 15%, binder 20% and biuret 0-6% over the batch were prepared. The composition containing 6% biuret over the batch was insensitive to friction and impact. As the amount of biuret was increased, the energy, burning rate and sensitivity decreased, whilst the auto ignition temperature increased. The formulation containing 4% biuret over the batch was found to be the optimum with respect to energy, burning rate, pressure index, and sensitivity.