为进一步提高HTPB推进剂的能量并抑制铝粉在燃烧过程中的团聚,制备了铝粉质量分数为16%～22%的端羟基聚丁二烯(HTPB)推进剂,并分别加入含氟有机化合物(OF)作为铝燃烧促进剂,研究了铝含量和OF对HTPB推进剂燃烧性能的影响; 使用氧弹量热仪测定了推进剂在氩气氛围下(3MPa)的爆热; 收集在3MPa下推进剂燃烧的凝聚相产物,采用激光粒度仪、X射线光电子能谱仪(XPS)及X射线衍射仪(XRD)等分别对其进行粒度分布、元素和物相分析; 通过线扫描摄像机和高压燃烧室系统测定推进剂的燃速; 利用高速摄影系统观察推进剂燃面上熔铝粒子的团聚过程。结果 表明,HTPB推进剂在铝粉质量分数为20%时实测爆热最大,含氟有机物OF的引入使得爆热有所下降; 随着HTPB推进剂中铝含量的提高,燃面上熔铝粒子的团聚愈加严重,凝聚相燃烧产物的尺寸和残留铝含量均逐渐增加; 加入含氟有机物OF能够促使 -Al2O3和AlF3的生成,有效抑制铝颗粒在燃烧过程中的团聚,使凝聚相燃烧产物的尺寸和残留铝含量显著降低,当铝粉质量分数为20%时,OF的加入使得残留铝的生成率降低了50%; 较低的铝含量和OF的添加有利于HTPB推进剂燃速的提高。
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.
