New method to prepare the lowest eutectic mixture of MTNP/DNTF and its properties

In this work, differential scanning calorimetry tests are performed on eutectic mixtures of 1-methyl-3,4,5-trinitropyrazole (MTNP) and 3,4-bis(3-nitrofurazan-4-yl)furoxan (DNTF) with different molar ratios, phase diagrams of the melting temperature and composition and those of the melting enthalpy and composition are constructed. Then, the ratio of the lowest eutectic system is obtained on the basis of the phase diagrams, and the lowest eutectic mixture of MTNP/DNTF is characterized by energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric mass spectrometry, mechanical sensitivity test, and detonation performance calculation. The results show that the ratio of the lowest eutectic system of MTNP/DNTF is $70.3/29.7$, and the melting point is $78.9^\circ$C, which is very close to the melting point of TNT. Raw MTNP and raw DNTF can be uniformly mixed to form the lowest eutectic, and there is no chemical reaction between the raw materials, only a certain intermolecular force exists. The products of thermal decomposition are $\mathrm{H}_2\mathrm{O}$, $\mathrm{NO}$, $\mathrm{N}_2\mathrm{O}$, and $\mathrm{CO}_2$. The lowest eutectic mixture also has lower mechanical sensitivity and excellent detonation performance. Thus, the lowest eutectic mixture has a potential to replace molten cast TNT-based explosives, thereby meeting the demands of modern weapons and equipment.