Energetic additive C6N30H15Co: In situ physicochemical enhancement of the thermal decomposition of ammonium perchlorate

Making solid propellants into porous structures can significantly improve combustion speed and reduce energy density. To balance this contradiction, this work developed a novel dual mechanism additive composed of the energetic compound bis-(1(2)H-tetrazol-5-yl)-amine coordinated with a cobalt atom (BTA-Co). This additive decomposes prior to ammonium perchlorate (AP), undergoing violent swelling that results in a porous material characterized by a well-defined three-dimensional structure, loaded with nano metal oxides. This architecture aims to provides dual-mechanism enhancement effects, which include both physical gas convection provided by organic frames and chemical electron transfer provided by metal oxides. The hypothetico-deductive method was used to corroborate the additive enhancement mechanism from the morphology, composition, and enhancement laws on AP decomposition of the post-combustion products generated in different atmospheres. And direct evidence of the physical and chemical mechanisms was obtained through termination combustion method, TG-MS, and Real-time FTIR testing. The TG-DSC results demonstrated that the addition of 5 wt% BTA-Co significantly reduced the high-temperature decomposition temperature of AP by 116.6 °C and increased the heat release by 10.34-fold. Additionally, the burn rate of AP-Al-HTPB solid composite propellant with 2 wt% BTA-Co increased by 28.87 %. This study provides essential empirical data and theoretical insights for the development of new combustion additives and high-burn-rate AP-based composite solid propellants.