Prediction of crystal form and study on crystal growth characteristics of TKX-55—a novel heat-resistant energetic material

Abstract

5,5′-Bis(2,4,6-trinitrophenyl)-2,2′-bi(1,3,4-oxadiazole) (TKX-55) is a new type of heat-resistant energetic material with excellent detonation performance. To study the crystal particle morphology and size control of TKX-55, this study predicted the crystal structure of TKX-55 through quantum chemistry and molecular dynamics simulations as well as simulated and analyzed the crystal morphology changes that occur under the influence of specific solvents and crystal habit modification. Based on the simulation results, this study designed five different recrystallization methods and prepared recrystallized products with different morphologies and particle size distributions. The crystal growth mechanism was analyzed and discussed. The morphology and structure of the recrystallized samples were characterized using scanning electron microscopy, powder x-ray diffraction, and infrared spectroscopy techniques. The thermal properties of the recrystallized samples were tested using differential scanning calorimetry and thermogravimetric analysis. The impact sensitivity of the recrystallized sample was tested, and it was found that the impact sensitivity of the recrystallized product was significantly lower than that of the TKX-55 raw material. Through the combination of simulation and experiment, this study ultimately obtained three morphology rules, narrow particle size distribution, and effectively improved the safety of heat-resistant energetic material crystal particles.