超声辅助喷雾法制备超细高品质HMX及其晶型控制

摘要

To prepare ultrafine and high-quality octogen(HMX) and study its crystal types,superfine HMX was prepared by an ultrasonic assisted spray recrystallization refinement method.The effects of atomization rates,solvent and non-solvent type and temperature etc.on the particle morphology and crystal types of HMX were studied.The crystal morphology,particle size and crystal type of HMX were characterized by scanning electron microscopy (SEM) and X-ray diffractometer (XRD).The thermal decomposition properties of HMX were measured by differential scanning calorimetry (DSC).The impact sensitivity of raw HMX and superfine HMX was measured by an impact sensitivity tester.Results show that the ultrafine HMX prepared by ultrasonic assisted spray recrystallization refining has a great influence on the atomization rates,solvent and non solvent type,temperature etc.The morphology of HMX crystals prepared by an ultrasonic frequency of 40 kHz,stirring speed of 400 r · min-1,atomization rate of 20 mL · min-1,acetone as solvent,absolute alcohol as non-solvent and temperature of 30 ℃ is the best,the crystal type isβ-type.Compared with the raw material of HMX,the apparent activation energy of thermal decomposition reaction of ultrafine HMX increases by 17.94 kJ · mol-1 and its characteristic drop height of impact sensitivity increases by 29.6 cm.%为制备超细高品质奥克托今(HMX)并研究其晶型,采用超声辅助喷雾重结晶细化法制备了超细HMX,研究了雾化率、溶剂与非溶剂的种类、温度等对HMX的晶体形貌及晶型的影响.采用扫描电子显微镜(SEM)、X射线衍射仪(XRD)对HMX的晶体形貌、粒径和晶型进行了表征.采用差示扫描量热仪(DSC)测试了HMX的热分解性能.用撞击感度仪测试了原料HMX和超细HMX的撞击感度.结果表明,采用超声辅助喷雾重结晶细化法制备的超细HMX受雾化率、溶剂与非溶剂的种类、温度等影响较大.超声频率为40 kHz,搅拌转速为400 r·min-1,雾化率为20 mL·min-1,丙酮为溶剂,无水乙醇为非溶剂,温度为30℃制备出的HMX晶体形貌最佳,晶型为β型,与原料HMX相比,超细HMX的热分解表观活化能升高17.94 kJ·mol-1,撞击感度特性落高升高29.6 cm.