Mechanistic analysis and performance comparison of core-shell assembled molecular perovskite energetic materials in HTPB propellant

In-situ assembly of three molecular perovskite energetic materials (DAP-2, DAP-4, and DAN-2) with ammonium perchlorate as the energetic eutectic oxidizer, the performance mechanism of hydroxyl-terminated polybutadiene propellant was investigated. This comprehensive study examined the thermal decomposition behavior and combustion-agglomeration characteristics of the eutectic oxidizers at pressures of 0.1–8.0 MPa. Experimental results demonstrated that the synthesized molecular perovskite energetic eutectic oxidizers exhibited significant redox reactions during thermal decomposition and combustion within the propellant. The reactions were accompanied by releasing superoxide ions, which notably enhanced combustion performance and energy release. The eutectic core-shell structure improved interfacial contact, leading to increased heat and mass transfer efficiency. As a result, shorter combustion times and increased burning rates were observed, with DAP-4 demonstrating the best overall performance among the five energetic materials. Additionally, the average agglomerate sizes ( D 50 ) for RDX, HMX, DAP-2, DAP-4, and DAN-2-based propellants near the burning surface were 161.11 μm, 92.51 μm, 40.64 μm, 30.30 μm, and 41.16 μm, respectively. The agglomeration degree of the propellants based on molecular perovskite energetic materials was significantly lower than that of the RDX and HMX-based propellants. This reduction in agglomeration is attributed to the thin molten skeleton layer and the high-temperature oxidizing gases produced by the molecular perovskite energetic eutectic oxidizers, which effectively suppressed aluminum particle agglomeration near the burning surface. This dual mechanism ultimately resulted in a significant enhancement in propellant performance.