Preparation Of The Spherical CL-20 Based On The Microfluidic Technology

The raw hexanitrohexaazaisowurtzitane?CL-20?has sharp edges and corners,which is not conducive to the subsequent molding process and limits its application.The spherical CL-20 can effectively solve this problem.However the size of the CL-20 microspheres prepared by traditional the process is not uniform.In this study,microfluidic technology was used to prepare CL-20 microspheres.The research contents are as follows:?1?CL-20 microspheres was prepared a T-type microchannel device in which the CL-20 in ethyl acetate solution is disperse and the surfactant aqueous solution is the continuous phase.The suitable curing condition were studied by changing the temperature and concentration of the surfactant solution.The results showed that when the temperature was 60°C and the surfactant concentration was 2%,the CL-20 microspheres had a good curing effect.The surface of the CL-20microspheres was relatively smooth,with many internal particles stacked together,and the internal voids were much smaller.The shell thickness is about 8?m.?2?The particle size of CL-20 microspheres can be controlled by changing the flow rate of the continuous phase,the concentration of the dispersed phase and the concentration of the surfactant solution.The results showed that when the continuous phase flow rate?Q_c?increased from 400?L·min^-1 to 800?L·min^-1,the average particle size of CL-20 microspheres decreased from 106.8?m to 74.6?m,the coefficient of variation was less than 8.5%,and particle size decreases with increasing continuous phase flow rate;when the concentration of dispersed phase decreases from 4.8%to 3.4%,the average particle size of CL-20microspheres decreases from 91.6?m to 74.9?m,the dispersion coefficient is less than 7.5%,and particle size decreases with decreasing concentration of the dispersed phase;when the surfactant concentration increases from 2%to 3%,the morphology of the CL-20 microspheres becomes irregular and the sphericity becomes poor.The particle size of CL-20 microspheres first decreases and then increases with increasing surfactant concentration.The comprehensive analysis of X-ray diffractometer,infrared spectrum and differential scanning calorimeter reveal that,the crystal form of CL-20 microspheres prepared under different process conditions was?-type form,and the thermal decomposition temperature was basically consistent with that of the raw materials.The apparent activation energy of the hollow spherical CL-20 was increased by 30 kJ·mol^-1.The impact sensitivity was decreased by 80%compared with the raw CL-20.The friction sensitivity was also dcreased by 24N.The mechanical sensitivity was significantly reduced.Microfluidics provides a new method for the preparation of spherical CL-20.