The Synergistic Effect of Fe-Based MOFs and HTPB on AP Decomposition in Solid Propellants

Abstract

[Abstract] Many factors and their mutual interaction between catalysts and AP/HTPB composite solid propellant induce the complexity in the combustion. Among them, we prepared two Fe-based MOFs as catalysts and investigated their catalytic effects and mechanism on the decomposition AP, HTPB and AP/HTPB complex by TG-DSC and TG-IR. The results show that both Fe-based MOFs exhibit catalytic effects on the decomposition of all samples. Specifically, in the AP/HTPB/MOFs composite system, a synergistic effect between MOFs and HTPB is observed, substantially accelerating the decomposition of both AP and HTPB, which makes the HTD temperature of AP advance approximately 100 °C, beyond what would be expected from each component acting independently. Mechanistic studies demonstrate that Fe2O3@C produced by the decomposition of Fe-based MOF uses the decomposition products of HTPB as a bridge to accelerate the overflow of NH3 on the surface of AP, thereby allowing AP to decompose rapidly at a lower temperature and also accelerating the decomposition of HTPB. Moreover, its influence on the combustion performance of AP-based composite propellants was studied and the combustion rate increased by 20%. This research provides the new directions for designing and applying of Fe-based MOFs materials in HTPB-based solid propellent.