Theoretical research on performances of CL-20/HMX cocrystal explosive and its based polymer bonded explosives (PBXs)...

In this article, the CL-20/HMX cocrystal model was established and its based polymer bonded explosives (PBXs) were designed. The static performances, including mechanical properties, stability and detonation performance of CL-20/HMX cocrystal model and PBXs models, were predicted by molecular dynamics (MD) method. The mechanical parameters, binding energy, and detonation parameters of PBXs models were calculated and compared with that of pure CL-20/HMX cocrystal model. The influence of polymer binders on performances of CL-20/HMX cocrystal explosive was evaluated. Results show that the polymer binders make the engineering moduli (tensile modulus, shear modulus, and bulk modulus) of PBXs declined and Cauchy pressure increased, meaning that the polymer binder can obviously improve mechanical properties of CL-20/HMX cocrystal explosive, and the PBXs model with fluorine rubber (F₂₃₁₁) has the best mechanical properties. In different PBXs models, the binding energy between CL-20, HMX molecules and F₂₃₁₁ is higher than other polymer binders, indicating that the CL-20/HMX/F₂₃₁₁ model is more stable. The PBXs models have lower value of crystal density and detonation parameters compared with pure CL-20/HMX cocrystal and the energetic performance of PBXs is weakened. The PBXs model with fluorine resin (F₂₃₁₄) has the highest energetic performance and it is higher than pure HMX. Therefore, the CL-20/HMX/F₂₃₁₁ and CL-20/HMX/F₂₃₁₄ models have more favorable comprehensive properties, proving that F₂₃₁₁ and F₂₃₁₄ are more preferable and promising to design CL-20/HMX cocrystal based PBXs.