Preparation of porous CL-20/FOX-7@AP composite microspheres to enhance safety and energy release efficiency

The proportion of oxidizer in the formulation of composite solid propellants (CSPs) is often more than 50 %. It is very important to explore the preparation of new high-energy oxidizers to improve the energy performance of CSPs. Porous CL-20/FOX-7@AP composite microspheres were prepared by combining high-energy density CL-20 and high safety FOX-7 with traditional oxidant AP through microchannel recrystallization technology coupled with solvent evaporation induced self-assembly technology. The experimental results show that the morphology of porous CL-20/FOX-7@AP composite microspheres is regular, and AP is uniformly attached to the surface of porous CL-20/FOX-7 composite microspheres. Compared with CL-20/FOX-7 composite microspheres, the oxygen balance of CL-20/FOX-7@AP increased from −14.12 % to −8.47 %, and the minimum impact excitation energy of CL-20/FOX-7@AP-1 and CL-20/FOX-7@AP-2 increased by 2.25 J and 3.25 J, respectively. When CL-20/FOX-7@AP-1 and CL-20/FOX-7@ AP-2 were used as new oxidants to replace 10 % AP in CSPs formula, the burning rate increased by 21.52 % and 27.85 % respectively, and the pressurization rate increased by 69.79 % and 75.44 % respectively. CL-20/FOX-7@AP composite microspheres with a porous synergistic core-shell structure are expected to be used as novel high-energy oxidants in CSPs to improve the energy density and energy release efficiency of CSPs.