Promoting the ignition and combustion performance of Al/CL-20/AP solid propellant by synergistic effects of graphene-based catalysts and interfacial control

High burning rate pressure exponent and incomplete combustion of Al constrains the further application of the composite propellant containing CL-20. In this study, various Al@CL-20 composites constructed by spray-drying method were applied to modify the HTPB/AP/Al/CL-20 propellant through interfacial control and synergistic effect of catalysts (GO[sbnd]CHZ-M, M=Co²⁺ or Ni²⁺) without changing the propellant formulations. The results show that the modified propellant have a greater heat of reaction (5977 J g^-1, increased by 7.3 %), a reduced ignition delay time of 477 ms, an 32.1 % increase in the burning rate at 1 MPa, and the pressure exponent decreased from 0.49 to 0.15 within 0–2 MPa (about 69.4 % reduction), the mechanism can be attributed to the catalytic decomposition of CL-20 and AP by the presence of GO[sbnd]CHZ-M. Moreover, the agglomeration of Al was remarkably inhibited by interfacial control and precise catalysis, the proportion of condensed phase combustion products with particle size larger than 10 μm decreased from 35.1 % to 23.4 %, while the active Al content in the products declined significantly, indicating that the combustion efficiency of the propellant was greatly improved.