Thermal expansion characteristics of high energy insensitive explosive α-NTO

ABSTRACTThermal expansion is an important structural parameter to evaluate the structural stability and performance reliability of energetic materials. In order to further understand the thermal expansion characteristics and mechanism of high-energy insensitive explosive 3-nitro-1, 2, 4-triazol-5-one (NTO), the thermal expansion characteristics of α-NTO were studied by in-situ X-ray diffraction (XRD) technique. Based on the Rietveld full-spectrum fitting structure refinement principle, the thermal expansion coefficient of α-NTO was obtained. The results show that α-NTO exhibits obvious reversible anisotropic thermal expansion under the action of thermal field. Based on infrared and Raman spectroscopy combined with theoretical calculation methods, the crystal packing structure of α-NTO at different temperatures and its correlation with thermal expansion characteristics were studied. It is believed that the functional groups that produce hydrogen bonds and hydrogen bond receptors in the crystal structure of α-NTO under thermal stimulation play a leading role. At the same time, compared with the thermal expansion characteristics of other explosive crystals, the influence of crystal packing on the thermal stability of explosive crystal structure was analyzed. The results show that the thermal expansion anisotropy of layered packing explosive crystals with strong hydrogen bonding is more obvious.KEYWORDS: Crystal packingin-situ X-ray diffractionNTOthermal expansion AcknowledgmentsThank you to the State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, and the Institute of Chemical Materials, China Academy of Engineering Physics for their support.Disclosure statementNo potential conflict of interest was reported by the author(s).Data availability statementThe data that support the findings of this study are available from the corresponding author upon reasonable request.Supplementary materialSupplemental data for this article can be accessed online at https://doi.org/10.1080/07370652.2023.2268056Additional informationFundingThis research were funded by the National Natural Science Foundation of China, grant number 22275177 and grant number 21975234.