| Numerous studies have shown that RDX’s friction, impact and shock sensitivity reduce and the release rate of energy enlarge with the RDX particle size decreased. The low sensitivity is more obvious when RDX is to be nano. There are some general methods to prepare nano RDX, such as sol-gel method, solvent/non-solvent recrystallization method, supercritical fluid method and so on. Howerver, these methods of preparation of nano RDX exist lots of shortcomings, like little output, post-processing complex, poor repeatability of experiments, serious environment pollution etc. The paper does research on batch preparation of nano RDX by using the pulverized machine HLG-5and explores nano RDX’s application in PBX mixed explosive. The main contents are as follows:Firstly, Working out the technological parameter of pulverized machine HLG-5for preparing nanometer RDX. Monitoring the nano process sample in real time by using laser particle analyzer and also analyzing some factors on nano RDX which cover grinding medium filling amount, milling time, rotational speed, concentration and so on. Then I get the optimal technological parameter for the nanocrystallization process which are as follows: distribution and fluid mode, filling quantity of60%medium, concentration of materials10%,1200r/min speed, grinding120times.Secondly, Researching the dry method of nano RDX and the purity of dried products. In the meantime, analyzing the influence on particle size, dispersed state, productive rate and so on, after the nano RDX drying that compared with four methods which are ordinary drying, vacuum heating drying, supercritical drying and vacuum freeze drying. After experiment, the result is that vacuum freeze drying is the most suitable method for nano RDX drying. The nano RDX is higer pure than industrial raw material RDX through three analysises like infrared spectroscopy, inductively coupled plasma emission spectrometry and X-ray diffraction.It shows that the nano RDX has no residual liquid, no crushing imputiry and its crystal is constant.Thirdly, the study still covers thermal properties and sensitivity about nano RDX. In the experiment, I adopt five test methods to test nano RDX and these test methods are TG, DSC,5S breaking point test. Compared with the industrial raw materials, the laboratory finding is that the thermal decomposition peak temperature of nano RDX and the outbreak of5s is slightly bring forward, activation energy reduce to8.667kJ/mol which is decrease by6.61%, friction sensitivity is reduced by30%, impact sensitivity is reduced92.8%, shock sensitivity is reduced by51%. Howere, the electrostatic sensitivity and flame sensitivity are equal to the raw materialLastly, exploring the application of nano RDX in PBX mixed explosive (Black-2). Using water suspension method to prepare PBX mixed explosive powder which contains nano RDX and analyze the powder’s thermal decomposition performance. I still figure out thermodynamic parameters such as thermal decomp-osition temperature, activation energy, self ignition temperature etc. |
