New Insensitive Plastic-Bonded Explosive Sheet (Explosive Properties and Thermal Decomposition Characteristics)

In recent years, 3-nitro-1,2,4-triazol-5-one (NTO) has been widely incorporated into energetic formulations because it reduces sensitivity while maintaining satisfactory detonation performance. In this work, a polymer-bonded explosive (PBX) sheet containing pentaerythritol tetranitrate (PETN), NTO, and hydroxyl-terminated polybutadiene (HTPB) was prepared by a solventless cast-cured method. The impact and friction sensitivities of the prepared PBX were evaluated using the OZM-BAM Fall Hammer and the OZM-BAM Friction Apparatus, respectively. The detonation characteristics of the formulation were calculated with Explo5 software, while the detonation velocity was measured using the OZM-VOD 812 instrument. The thermal decomposition kinetics of the PBX were investigated through the isoconversional It-OFW, Friedman, and Vyazovkin methods, together with the Kissinger method. The lifetime of the formulation was estimated under selected isothermal and STANAG climatic conditions using the Advanced Kinetic and Thermokinetic Software (AKTS). The developed PBX exhibited an impact energy of 35.9 J, while its friction sensitivity exceeded the upper measurement limit of the apparatus (360 N), indicating low sensitivity to mechanical stimuli and ensuring safety during handling and transportation. It also demonstrated a measured detonation velocity of 6992 m s −1 and a calculated heat of detonation of 4514 J g −1 . Thermal analysis indicated that the PBX decomposes through two distinct stages. The first decomposition stage exhibited average activation energies of 165, 164, 151, and 187 kJ mol −1 , as determined using the It-OFW, Friedman, Vyazovkin, and Kissinger methods, respectively. However, the second decomposition stage showed substantially higher average activation energies of 390, 410, 348, and 463 kJ mol −1 , respectively. Isothermal simulations estimated that the PBX may reach 50% conversion at 100°C after 55 days and complete conversion at 150°C within 17 days. In addition, simulations conducted under STANAG conditions estimated that the PBX formulation would undergo limited conversion levels under A1 and A2 climatic conditions over 15 years. These results suggest that the developed PBX could serve as a safer alternative to PBX formulations based solely on highly sensitive explosives.