Contrasting thermolysis mechanisms and combustion behaviors of DAP-7/AP and DAP-7/Al mixture systems

DAP-7 as a novel molecular perovskite energetic material, ignites readily at ambient pressure but undergoes detonative combustion at 1 MPa, limiting its direct use in solid propellants. To harness its high energy while achieving controlled burning, we systematically investigated the thermolysis and combustion behaviors of binary DAP-7 mixtures with ammonium perchlorate and aluminum. Thermal analysis (DSC-TG, FTIR-MS, PY-GC–MS) reveals strong intermolecular interactions between DAP-7 and AP, which alter the original decomposition pathways, lower the initial decomposition temperature, and double the maximum mass loss rate compared to neat AP. Both AP and Al enable stable, self-sustained combustion of DAP-7 at ambient pressure. Optimizing the DAP-7/AP ratio (AP:10–20 wt%) significantly enhances the burning rate, while adding Al (10–20 wt%) also increases the burning rate relative to neat DAP-7, with the best combustion efficiency (smallest condensed-phase particle size, D ₉₀ = 5.1 μm) achieved at 30% Al. The improved Al combustion is attributed to HCl-mediated etching of the native Al₂O₃ passivation layer. Both additives thus convert the explosive nature of neat DAP-7 into stable, high-rate combustion, making DAP-7/AP and DAP-7/Al mixtures promising candidates for high-burn-rate solid propellants.