Performance of Ammonium-Perchlorate-Based Composite Propellant Containing Nanoscale Aluminum

摘要

Several composite propellant mixtures of hydroxyl-terminated polybutadiene, ammonium perchlorate, and aluminum were prepared with and without the addition of small percentages of nanoscale aluminum and tested in a strand burner at pressures up to 34.5 MPa. The effect of monomodal versus bimodal ammonium perchlorate particle size, coarse aluminum particle size, nano aluminum particle size, and coarse-to-fine ratios on burning rate and manufacturability were explored. A significant conclusion of the present study is that the addition of nanoscale aluminum does not always ensure an increase in the propellant's burning rate when produced using conventional methods. It was observed that over the range of mixtures and pressures explored, a bimodal oxidizer is required for the nanoscale aluminum to affect the burning rate, and that a monomodal oxidizer tended to nullify any influence of the nanoscale aluminum. In some cases, the addition of nanosized aluminum decreased the burning rate. The level of burning-rate increase or decrease depended on the bimodal or monomodal ammonium perchlorate particle sizes, the coarse aluminum particle size, and the pressure range.