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

  • Mrinal Ghosh High Energy Materials Research Laboratory, Pune
  • V. Venkatesan High Energy Materials Research Laboratory, Pune
  • Arun Kanti Sikder High Energy Materials Research Laboratory, Pune
  • Nirmala Sikder High Energy Materials Research Laboratory, Pune
Keywords: Solvent evaporation, precipitation, ultrasonication, true density

Abstract

ε-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, ε-CL-20 is scaled up to 500 g batch. Raw CL-20 was assigned to α-CL-20. The chemical and polymorphic purity of prepared ε-CL-20 was found to be about 98 per cent and > 95 per cent, respectively. ε-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 ε-CL-20 by solvent evaporation method with and without in-situ ultrasonication and also by precipitation methods is about 30 μm - 40 μm, 150 μm - 200 μm and 150 μm - 300 μm, respectively. The measured true density of prepared ε-CL-20 by precipitation method with 100 g and 500 g batch scale using Helium gas pycnometer was 2.038 g/cm3 and 2.043 g/cm3, respectively. The lower value of calculated void percentage of ε-CL-20 (0.05-0.29%) indicate better crystal quality. Conclusively, prepared ε-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.

Defence Science Journal, 2012, 62(6), pp.390-398, DOI:http://dx.doi.org/10.14429/dsj.62.1428

Author Biographies

Mrinal Ghosh, High Energy Materials Research Laboratory, Pune
Shri Mrinal Ghosh obtained his MTech from Indian Institute of Technology, Delhi in 2005. Presently working as Scientist C at High Energy Materials Research Laboratory (HEMRL), Pune. His research area includes: Polymorphism in crystalline explosive materials their preparation and characterization, vibrational spectroscopy and electron microscopic analysis.
V. Venkatesan, High Energy Materials Research Laboratory, Pune
Dr V. Venkatesan obtained PhD (Chemistry) from Indira Gandhi Centre for Atomic Research, Kalpakkam in 2003. Presently, he is working as Scientist ‘D’ at HEMRL, Pune. His research and work experiences include: condensed phase and gas phase spectroscopy, crystallisation, polymorphism, molecular and its cluster structure determination and computational calculations.
Arun Kanti Sikder, High Energy Materials Research Laboratory, Pune
Dr AK Sikder presently working as an Associate Director at the HEMRL, Pune. He has published about 85 research papers in national/ international journals. Earlier he worked on highly toxic organophosphorus compounds used as chemical warfare agents and their antidotes. His research work includes: High energy materials in a wide spectrum of subjects of defence
Nirmala Sikder, High Energy Materials Research Laboratory, Pune
Dr (Mrs) Nirmala Sikder obtained her PhD from Jiwaji University, Gwalior, in 1996. Presently she is working as a Scientist at the HEMRL, Pune. She has published more than 35 papers in national/international journals. Earlier she worked on synthesis, characterization and hydrolysis studies on toxic organophosphorus compounds. Her research includes: Synthesis of high energy materials and their instrumental analysis.
Published
2012-11-12
How to Cite
Ghosh, M., Venkatesan, V., Sikder, A., & Sikder, N. (2012). Preparation and Characterisation of ε-CL-20 by Solvent Evaporation and Precipitation Methods. Defence Science Journal, 62(6), 390-398. https://doi.org/10.14429/dsj.62.1428
Section
Armaments & Explosives

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