Mechanochemical fabrication and properties of CL-20/RDX nano co/mixed crystals

Abstract

By milling 2,4,6,8,10,4,6,8,10, and hexahydro-1,3,5trinitro-1,3,5-triazine (RDX) together, a nano CL-20/RDX co/mixed crystal explosive with a mean particle size of 141.6 nm is prepared from the raw materials, and the co/mixed crystals are characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, infrared (IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC) and thermal-infrared spectrometry online (DSC-IR) technology; furthermore, the impact, friction and thermal sensitivity of the samples are tested. The results show that after milling, the morphology of the co/mixed crystal explosive is near-spherical, and the particle size reveals a normal distribution. The milled sample showed the same molecular structure and surface elements as the raw materials, but the XRD test shows that CL-20/RDX has a new crystal phase and the Raman and IR spectra gave a supplementary confirmation for the existence of a cocrystal phase in the milled sample. The activation energy of the thermal decomposition of CL-20/RDX is 206.49 kJ mol À1 higher than that of raw RDX. DSC-IR analysis showed that the thermolysis of CL-20/RDX produces a large amount of CO 2 and N 2 O and a small amount of H 2 O, NO 2 and NO. The mechanical sensitivity of CL-20/ RDX is very low. In impact sensitivity tests with a 5 kg hammer, the special height (H 50 ) is 51.43 cm, which is higher than the values of 36.43 cm for raw CL-20 and 9.78 cm for raw RDX. In the friction sensitivity tests, the explosion probability (P) is 56%; however, the thermal sensitivity of CL-20/RDX is higher than that of the raw materials, with its 5 s burst point being only 243.51 C. rsc.li/rsc-advances 34126 | RSC Adv., 2018, 8, 34126-34135 This journal is

Nitramine-Based Energetic Cocrystals with Improved Stability and Controlled Reactivity

“…Some reports in the literature on the synthesis of CL-20 cocrystals with other nitramines include the following: CL-20/HMX cocrystals and CL-20/RDX cocrystals. From the reported results, CL-20/RDX cocrystals are usually formed in ratios of 1:1 and 1:2 via EM and GM methods, which was confirmed on the basis of spectral and other analytical techniques. The formation of CL-20/RDX cocrystals is driven by C–H···O hydrogen bonds between -NO 2 and −CH 2 .…”

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