Of Micro/nano Hmx Prepared By Sol - Gel/cr < Sub > 2 < / Sub > O < Sub > 3 < / Sub > And Micro/nano Composite Particles Hmx

In this paper, Superfine HMX/Cr2O3composites particles and superfine HMX particles were prepared by the method of sol-gel. the sol-gel process and the gel-forming mechanism were investigated based on theories. According to the reunion mechanism of nano particles in the dry process, different drying methods were used in order to prevent particles’ agglomeration in the dry process.Firstly, Combining sol-gel and the ordinary drying、supercritical drying method respectively, the superfine HMX/Cr2O3composites particles were prepared. After dissolved the Cr2O3by dilute hydrochloric acid, superfine HMX particles were prepared.The result showed that, the optimum experimental conditions is:precursor’s concentration is1.0712mol/L, the reaction temperature is25℃, the mole ratio of precursor to1,2-propylene oxide is1:11, and the reaction time is1.5hours.Secondly, superfine HMX/CrO3composites particles and superfine HMX were characterized by TEM、SEM and Laser particle size analyzer. The result showed, two granulated grades of submicron and nano HMX/Cr2O3composites particles were prepared by sol-gel method; both micro and submicro HMX particles were also prepared by this method; Compared with DMF, when acetone is used as solvent of HMX, particle d50of HMX is smaller and the particle size distribution are more narrow, the maximum d50is5.21μm and minimum is0.29μm; with the constantly increasing contention of HMX in HMX/Cr2O3, the particle diameter d50of HMX decreases; compared with the common drying method, when the supercritical drying method is used, particle d50of HMX is smaller, and the particle size distribution is more narrow.Lastly, the thermal decomposition and mechanical sensitivity of two granulated grades of HMX/Cr2O3composites particles and HMX particles were studied,. The result suggested that, compared with micron HMX/Cr2O3composites, the decomposing exothermic peak of nano HMX/Cr2O3move ahead、the content of explosives decreases; Compared with the industrial HMX,the particle diameter d50of which is75.46μm, the apparent activation energy、impact and friction sensitivities of submicro HMX decreases, the decomposing exothermic peak move ahead.