Regulating the thermal stability and sensitivity of DNTF via refinement and encapsulation engineering

Abstract

Energetic materials have important strategic value in the fields of national defense and civil use, and DNTF has become a widely preferred object in the field of energetic materials due to its advantages of high density, high energy, and low pollution, but its high sensitivity has always hindered its application and development. In this work, based on the background, the refinement and encapsulation methods were combined to improve its sensitivity. Firstly, the raw DNTF was refined, and then fluororubber (F₂₆₀₃) was coated to prepare polymer-bonded explosives (PBXs). Then the morphology and structure were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The thermal properties were evaluated by thermogravimetry-differential scanning calorimetry (TG-DSC) and pressurized differential scanning calorimetry (PDSC). The mechanical sensitivity was evaluated by impact sensitivity and friction sensitivity tests. The results show that F₂₆₀₃ is successfully coated on the surface of DNTF. Compared to the pure DNTF, the thermal volatilization rate of DNTF coated with F₂₆₀₃ decreased, and its activation energy (E) and the critical temperature of thermal explosion (T_b) also increased significantly, indicating that its thermal stability was improved, which has been attributed to the thermal insulation effect of F₂₆₀₃. At the same time, F₂₆₀₃ coating can also effectively reduce the mechanical sensitivities of DNTF, and the sensitivity reduction effect of F₂₆₀₃ coating on refined DNTF is more significant due to the coating buffering effect of F₂₆₀₃, making it difficult to generate hot spots. Therefore, this study can provide theoretical guidance for improving the safety performance of DNTF and realizing a wider range of applications.