铝含量和含氟有机化合物对丁羟推进剂燃烧性能的影响

In order to further increase the energy of HTPB propellant and inhibit the agglomeration of aluminum particles during combustion, hydroxyl terminated polybutadiene (HTPB) propellants with aluminum contents(mass fraction) of 16%-22% were prepared, and an organic fluoride (OF) was separately added as the aluminum burning accelerator. The effects of aluminum content and OF on the combustion properties of HTPB propellant were investigated. An oxygen bomb calorimeter was used to measure the heats of explosion of propellants in argon atmosphere (3MPa). The particle size distribution, elemental contents and phase compositions of the solid combustion products of propellants at 3MPa were achieved by using the laser particle size analyzer, X-ray photoelectron spectroscopy (XPS) and X-ray diffractometer (XRD), respectively. The burning rates of propellant were tested by a line scanning camera and a high pressure chamber measurement system. The high-speed photographic system was used to observe the agglomeration process of the melting aluminum particles on the burning surface. The results show that the HTPB propellant has the largest heat of explosion with an aluminum content of 20%. The introduction of OF reduces the heat of explosion slightly. With increasing the aluminum content in HTPB propellant, the agglomeration of molten aluminum particles on the burning surface becomes more serious, and both the particle sizes and residual aluminum contents of the solid combustion products increase gradually. On the other hand, the addition of OF can promote the formation of γ-Al₂O₃ and AlF₃ and effectively inhibit the agglomeration of aluminum during combustion, thus greatly reducing the particle sizes and residual aluminum contents of combustion products. When the aluminum content is 20%, the addition of OF makes the active aluminum content of combustion product decrease by 50%. Besides, a lower aluminum content and the addition of OF are beneficial for enhancing the burning rate of HTPB propellant.