超重力辅助溶剂-反溶剂重结晶法制备亚微米级RDX

为了获得粒径分布均匀的细化RDX,在超重力反应器中,以丙酮-水作为溶剂-反溶剂重结晶体系,添加聚乙烯吡咯烷酮(PVP)作为表面活性剂,制备了亚微米级RDX。研究了RDX溶液浓度、PVP含量以及超重力反应器转速对RDX形貌和尺寸的影响,获得最优工艺条件,利用SEM、XRD和FT-IR对其形貌、晶体结构和分子结构进行了表征,并采用DSC研究了RDX的热分解过程。结果表明,在RDX溶液浓度为0.04g/mL、PVP浓度为0.2g/L、超重力反应器转速为1500r/min时,制备了平均粒径为0.54μm的亚微米级RDX,细化处理未改变RDX的晶型;与原料RDX相比,亚微米级RDX的分解峰温提前了1.2℃,热分解活化能从180~250kJ/mol降至约150kJ/mol。

Preparation of Submicron RDX Particles by High-gravity Assisted Solvent-Antisolvent Recrystallization Method

To obtain refined RDX with uniform particle size,submicron RDX was prepared through a high-gravity assisted solvent-antisolvent recrystallization method by using acetone-water medium as solvent-antisolvent system and the polyvinylpyrrolidone(PVP)as surfactant.The effects of RDX solution concentration,PVP concentration and rotating speed of high-gravity reactor on the morphology and size of RDX were studied,and the optimal process conditions were obtained.The morphology,crystal structure and molecular structure of RDX were characterized by SEM,XRD and FT-IR,and the thermal decomposition process of RDX was studied by DSC.Results show that the submicron RDX with a mean particle size of 0.54μm is obtained under the following optimized conditions:the RDX concentration is 0.04g/mL,the PVP content is 0.2g/L,and the rotating speed of RPB is 1500r/min.The refinement treatment does not change the crystal form of RDX.Compared with raw RDX,the decomposition peak temperature of submicron RDX is advanced by 1.2℃,and the decomposition activation energy of submicron RDX is decreased from 180—250kJ/mol to about 150kJ/mol.