Transition Metal Complexes Based on Hypergolic Anions for Catalysis of Ammonium Perchlorate Thermal Decomposition

Abstract

On the basis of hypergolic dicyandiamide (DCA) and cyanoborohydride (CBH) anions, 1-methyl-1,2,4-triazole (MTZ) ligand, and transition metal (Co/Ni/Cu) cations, five hypergolic coordination compounds (HCCs) were synthesized and characterized. Their molecular formulas were expressed as [Co(MTZ)4](DCA)2 (1), [Ni(MTZ)4](DCA)2 (2), [Cu(MTZ)2](DCA)2 (3), [Co(MTZ)4](CBH)2 (4), and [Ni(MTZ)4](CBH)2 (5). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) instruments were used to investigate the thermal decomposition behaviors of compounds 1–5, and the DSC instrument was used to investigate the catalytic effect of HCCs on the thermal decomposition of ammonium perchlorate (AP). High-temperature decomposition (HTD) of AP samples with 5% catalyst occurred immediately after low-temperature decomposition (LTD), and their HTD temperatures were lowered by 60–116 °C. The heat release of all samples is improved observably and is 2–3 times that of pure AP. Among them, compound 1 shows the best catalytic performance. The heat release of sample AP + compound 1 can reach 2291 J g–1, and the decomposition temperature can be advanced by 116 °C. The kinetic/thermodynamic parameters were calculated to further study the catalytic mechanism of HCCs on the thermal decomposition of AP. The research in this paper shows that HCCs were suggesting for a class of novel additives of composite propellants with improved combustion and energetic performances.