Preparation and Characterisation of epsilon-CL-20 by Solvent Evaporation and Precipitation Methods

epsilon-CL-20 is prepared from raw CL-20 by solvent evaporation and precipitation methods. Experiments were also done using solvent evaporation coupled with in-situ ultrasonication method. Using precipitation method, epsilon-CL-20 is scaled up to 500 g batch. Raw CL-20 was assigned to alpha-CL-20. The chemical and polymorphic purity of prepared epsilon-CL-20 was found to be about 98 per cent and > 95 per cent, respectively. epsilon-CL-20 was obtained agglomeration free with well defined geometry in comparison with raw CL-20 and its crystal morphology is dominantly bi-pyramidal or lozenge crystal shapes. The obtained mean particle size of prepared epsilon-CL-20 by solvent evaporation method with and without in-situ ultrasonication and also by precipitation methods is about 30 mu m - 40 mu m, 150 mu m - 200 mu m and 150 mu m - 300 mu m, respectively. The measured true density of prepared epsilon-CL-20 by precipitation method with 100 g and 500 g batch scale using Helium gas pycnometer was 2.038 g/cm(3) and 2.043 g/cm(3), respectively. The lower value of calculated void percentage of epsilon-CL-20 (0.05-0.29%) indicate better crystal quality. Conclusively, prepared epsilon-CL20 has high true density with less percentage of voids, less total moisture content and free from agglomeration as compared with the starting raw CL-20 material.