Study on the Properties of CL-20/NTO Based Pressed Mixed Explosive Under Typical Binder System

To achieve a balance between the high energy performance and the enhanced safety in mixed explosives, two mixed explosive formulations based on CL-20 and NTO were designed, and cellulose acetate butyrate (CAB) and fluoroelastomer (F2603) were selected as binders, respectively. A molecular dynamics simulation of the CL-20/NTO/binder system was conducted, and CL-20/NTO-based PBXs were prepared via the water suspension method. The properties of the CL-20/NTO-based PBX were subsequently investigated. The results indicated that the binding energy (E_bind) and cohesion energy density (CED) between CAB and CL-20/NTO were superior to the interactions observed between F2603 and the explosives. Furthermore, the morphology of powder particles in the CL-20/NTO-based PBX, utilizing both binder systems, yielded particles that were more intact, exhibiting ellipsoidal or globular shapes with uniform sizes. The activation energy of the PBXs prepared with the CAB binder system increased by 56.25 kJ·mol⁻¹ compared to that of CL-20, and were 6.11 kJ·mol⁻¹ higher than that prepared with the F2603 binder system, indicating the improved thermal stability of the CAB PBX. With the same composition of CL-20 and NTO, the CAB binder system demonstrated a higher detonation velocity, thus providing better energy performance. Slow cook-off test of the PBX using the CAB system at a heating rate of 2 K/min exhibited a combustion response level, whereas the F2603 system displayed the explosion behavior, suggesting that the CAB PBX system possesses superior insensitivity. Additionally, the influence of varying pressure and temperature on the formability of CL-20/NTO-based PBX under both binder systems was studied to enhance data support for the preparation of high-energy, blunt explosives.