Preparation and characterization of spherical submicron ε-CL-20 via green mechanical demulsification

Abstract

ABSTRACTThis report has developed a facile “green mechanical demulsification technology” which can emulsify submicron CL-20 particles greenly and submicron ε-CL-20 particles with stable crystal structure and favorable morphology were successfully prepared by this means. Simultaneously, CL-20 was also refined by spray recrystallization method and jet recrystallization method for better comparison. Structural characterizations and thermal stability of the composites were systematically studied by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimeter (DSC). Moreover, the safety performance was analyzed by qualitative testing of impact sensitivity and friction sensitivity. Compared with the raw CL-20, submicron CL-20 particles fabricated via the green mechanical demulsification technique were compact spheres with ε-CL-20 crystal form. The CL-20 refined by the spray recrystallization method and the spray recrystallization method exhibited irregular blocky structure and agglomerated needle-like structure, respectively. And the crystal forms of both CL-20 particles were converted from ε-CL-20 to β-CL-20. The activation energy of CL-20 refined via green mechanical demulsification technology was increased from 179.42 kJ/mol to 198.40 kJ/mol, thus enhancing the thermal stability. However, the thermal stability of the refined β-CL-20 showed a distinct decrease due to the transformation of the crystal structure. More importantly, the refined CL-20 particles possessed much lower impact sensitivity. The proposal of green mechanical demulsification method has availably settled the problems that the CL-20, with irregular morphology, is prone to crystal transformation, agglomeration, and environmental pollution. And there is a significant possibility that it is a promising green technology with comprehensive application foreground.