A novel high-energetic and good-sensitive cocrystal composed of CL-20 and TATB by a rapid solvent/non-solvent method

Abstract

Due to the insolubility of TATB in a majority of organic solvents, it is very difficult to prepare cocrystals of TATB. In this work, through a rapid nucleation solvent/non-solvent process, a novel cocrystal explosive, CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane)/TATB (1,3,5-triamino-2,4,6-trinitrobenzene), has been successfully prepared. The cocrystal is characterized with scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, thermogravimetric/differential scanning calorimetry (TG-DSC), and high performance liquid chromatography (HPLC). The SEM results indicate that the cocrystal particles are homogeneous with an average particle size of about 3–5 μm, and the morphology of the cocrystal is completely different from the primary materials. XRD and Raman analyses confirm that the cocrystal has unique peak patterns with large differences from CL-20 and TATB. IR and Raman spectra suggest that hydrogen-bonding interactions exist between CL-20 and TATB molecules. The density determination, the weight loss in one step and the single exothermic peak in the thermal analysis curves further illustrate that the CL-20/TATB cocrystal is a new substance instead of independent crystallization of CL-20 and TATB. In CL-20/TATB cocrystal, the molar ratio of CL-20 and TATB is 3 : 1 determined by HPLC. Thermal analysis and detonation parameters calculation shows that the cocrystal has excellent thermal stability and high energy-release efficiency. An impact sensitivity test indicates that the sensitivity of the cocrystal is sufficiently reduced relative to CL-20. For the CL-20/TATB cocrystal, its detonation performance is superior to HMX and impact sensitivity is almost the same as HMX.