通过自主设计搭建的设备,成功制备得到超细球形FOX-7颗粒,研究了工艺条件(包括溶剂/非溶剂体积比、溶液质量浓度、溶剂和非溶剂温度以及溶剂种类)对喷射结晶过程中FOX-7形貌的影响; 通过扫描电子显微镜、激光粒度分布仪、XRD衍射仪、差示扫描量热仪、热失重分析仪、撞击感度仪以及摩擦感度仪对样品的形貌、粒径分布、晶体结构、热性能以及机械感度进行表征和测试。结果 表明,与原料相比,制备得到的FOX-7颗粒形貌为球形,具有亚微米/微米级别的窄粒度分布(d10=0.703μm,d50=1.405μm,d90=3.446μm),晶体结构稳定; 相比于原料FOX-7,球形FOX-7表观活化能提高了14.62kJ/mol,机械感度明显降低,特性落高提高了42.2cm,摩擦感度较原料相比降低了80%。表明该喷射结晶过程具有产率高、效率高、易于实现大规模生产等优点,有望批量生产亚微米/微米级别的炸药颗粒。
The spherical FOX-7 was prepared successfully by a self-designed equipment, and the effects of different process conditions(such as the volume ratio of solvent/non-solvent, solution mass concentration, the temperature of solvent and non-solvent and different kinds of solvents)on the morphology of FOX-7 prepared by jet crystallization method were studied. The morphology, particle size distribution and crystal structures of all samples were characterized by field emission scanning electron microscopy(FE-SEM), laser particle size instrument and X-ray diffraction(XRD). Thermal analysis was performed by differential scanning calorimetry(DSC)and thermogravimetry(TG), and the impact and friction sensitivities of the samples were also tested. The results show that the spherical submicron/micron FOX-7 particles with a median particle size of 1.405μm, with the particle distribution ranges from 0.703μm(d10)to 3.446μm(d90), were fabricated successfully via jet crystallization method, and the particles exhibited stable structures. The apparent activation energy of spherical FOX-7 is increased by 14.62kJ/mol. The spherical FOX-7 is more insensitive than the raw FOX-7 with an increasement of 42.2cm of characteristic drop height of impact sensitivity and a reduction of 80% of friction sensitivity compared to the raw FOX-7. The jet crystallization method has the advantages of high yield, high efficiency, and achieving large-scale production easily,which has great potential value for the mass production of submicron/micron explosive particles.
