The DNTF coated by three polymers with enhanced thermal safety, combustion properties and decreased sensitivity

Abstract

3,4-Dinitrofurazanfuroxan (DNTF) is a highly energetic material with high sensitivity. For its handling safety, preparation of polymer-bonded composites is an effective approach. In this study, thermoplastic polyurethane (TPU), ethylene-vinyl acetate (EVA), and paraffin wax (PW) were used as coating agents to prepare DNTF-based composites. Coating methods of physical grinding, direct, and microcapsule methods were employed. Characterisation of the morphology and structure confirmed successful polymer coating on the DNTF particles. Thermal decomposition analysis was performed to determine which coating method provided the highest thermal stability. The composites coated with TPU and EVA using the direct method exhibited higher extrapolated starting temperatures and activation energies, indicating increased thermal safety. Therefore, the composites coated by the direct method were selected for further ignition, combustion, and sensitivity testing. All three composites burned stably in air. The ignition delay times of DNTF/TPU, DNTF/EVA, and DNTF/PW were shortened by 85.3 %, 25.85 %, and 81.3 %, respectively. All the composites also showed reduced sensitivity compared to uncoated DNTF. The impact sensitivity of DNTF/PW decreased by 99.4 %, and the friction sensitivity of DNTF/EVA decreased by 33.3 %.