制备工艺对HMX机械感度和热分解特性的影响

采用对原料奥克托今(HMX)筛分、球磨和溶剂/非溶剂重结晶等三种方法,制备出了不同形貌和粒度的HMX粉末。利用激光粒度仪和扫描电子显微镜(SEM)对样品进行了表征,并进行了撞击感度、摩擦感度及DSC测试,计算了三种HMX样品的表观热分解活化能。结果表明,筛分法制备的HMX样品,随着样品d50的减小,其机械感度没有明显的变化规律;球磨法制备的HMX样品,随着样品d50的减小,其撞击感度降低、摩擦感度升高;溶剂/非溶剂法制备的HMX样品,随着样品d50的减小,撞击和摩擦感度均降低。球磨法制备的HMX热分解活化能的平均值为262.184kJ.mol-1,明显高于溶剂/非溶剂法(238.902kJ.mol-1)和筛分法(242.343kJ.mol-1)。

Effect of preparation methods on mechanical sensitivity and thermal decomposition of HMX

Three kinds of HMX samples with different morphologys and particle sizes were prepared by screening,ball milling or solvent/non solvent methods,respectively,and characterized by laser granularity measurement and scanning electron microscope (SEM). The mechanical sensitivity and thermal decomposition of the samples were studied by impact sensitivity test,friction sensitivity test and DSC analysis. Results show that there are no obvious trends of the mechanical sensitivities depending on its d₅₀ for screening samples. However,for ball milling samples,the impact sensitivity reduces,and the friction sensitivity increases as its d₅₀ decreases. For solvent/non solvent samples,both the impact sensitivity and friction sensitivity decrease as its d₅₀ decreases. Moreover,the average value of activation energy of thermal decomposition for ball milling samples is 262.184 kJ·mol^-1,which is much higher than that (238.902 kJ·mol^-1 and 242.343 kJ·mol^-1) for the samples prepared by solvent/non solvent and screening methods.