| The power and safety of explosives are their most important properties,but there are mutual constraints between them.Generally,powerful explosives have poor safety performance.However,the preparation of insensitive high explosives is one of the main targets in the field of energetic materials.At present,cocrystal technology has become a new way to prepare high energy explosives.The existing technology usually takes a long time and has low output,so it is difficult to realize cocrystal engineering.In this paper,the spray crystallization method was used as the main research method to carry out engineering research,and the optimum technological conditions were obtained by optimizing the various technological conditions of the spray crystallization method.The amplification of CL-20/TNT、CL-20/HMX、CL-20/MTNP cocrystal was studied.At the same time,the rapid gasification of the solvent was used to carry out the cocrystal of CL-20/MTNP.However,this method is similar to the solvent volatilization method,which requires high solubility and is not suitable for engineering research,although the time consuming is shortened.Therefore,the spray crystallization method was mainly studied in engineering.Through research and analysis,the following conclusions have been drawn:（1）The CL-20/TNT cocrystal was prepared by solvent evaporation and jet crystallization.The two samples were characterized,and compared with the raw material components and their mixtures,the possibility of preparing cocrystal by jet crystallization was confirmed.（2）Several factors affecting spray crystallization（acetone used as solvent）were studied.The influencing factors:solvent/antisolvent ratio,stirring speed,temperature difference between solvent and non-solvent,feeding speed.To analyze the DSC and XRD and purity calculation,the results show that the ratio of solvent to non-solvent is 1:50,the stirring speed is 300r/min,the temperature difference between solvent and non-solvent is 20℃and the feed rate is 0.1ml/s.The cocrystal preparation of CL-20/HMX and CL-20/MTNP was carried out under acetone as the solvent and under the optimum technological conditions.（3）Three kinds of explosives（CL-20/TNT、CL-20/HMX、CL-20/MTNP）were amplified at 50g level by using the optimum process conditions.The yields of them are as follow:84.5%,86.38%,83.2%.（4）Based on the theory of solvent volatilization and vacuum distillation,CL-20/MTNP cocrystal was prepared by exploring the method of rapid vaporization of solvent.The results of SEM show that the CL-20/MTNP cocrystal is acicular,which is the same as that obtained by jet crystallization,but the particle size is larger.The DSC、XRD and sensitivity tests shows that the mass fraction CL-20/MTNP cocrystal explosive has changed compared with the raw material and has a good detonation velocity of 9163.3 m/s-1,which preserves the obtuse sensitivity of MTNP(H50=74.85).The rapid gasification of solvent can accelerate the speed of eutectic,but the solubility is very high as the solvent volatilization method,so it is limited to engineering,so it is necessary to continue to study. |
