Recrystallization&Coprecipitation Research On HMX

In this paper,the density and morphology of HMX under different conditions was studied by online control method,KNO3or nano-CuO coprecipitated with HMX,explored the better coprecipitation method, investigated the detonation velocity and sensitivity of the system.Specific content as follows:(1)HMX dissolution characteristics was measured by focused beam reflectance method (FBRM) and automatic reaction apparatus(Auto-Reactor).FBRM can track the particle real-timely in the solution,detect the dissolution or crystallization conditions of HMX,getting efficient and reliable test results.(2)HMX recrystallization in solvent system and solvent-anti-solvent system was studied by Auto-Reactor.Main rules as fellows:crystal morphology was mainly influenced by Solvent,such as HMX appeared serious "twin crystal" defect recrystalled in propylene carbonatesome solvent, while it generated solvate recrystalled in DMF, NMP solvent.Crystallization condition was obviously changed by adding anti-solvent, the proportion between solvent and anti-solvent had great influence on morphology, so did density,size and dispersity. From the crystal density perspective, the more anti-solvent the higher crystal density was;from crystal morphology perspective,if the proportion of anti-solvent was too high,it was difficult to get big particle size and smooth surface crystal. The conclusion showed that it generated higher density,neat crystalline form,smooth surface and good dispersion granular HMX recrystalled in solution system(normal propyl alcohol:1,4-butyrolactone=2:1).(3)The coverage of the coprecipitation explosive system in different experimental methods was investigated by adding KNO3or nano-CuO during the HMX recrystallization process,tested the performance parameters such as detonation velocity and sensitivity.It can draw a conclusion that the coprecipitation explosive system had most powerful activation when HMX coprecipitates with KNO3solution,and the activation was most obvious when the percentage of KNO3was about10%, the detonation velocity increased6.57%,accordingly,the mechanical sensitivity was higher;but HMX coprecipitated with nano-CuO could not improve detonation velocity.