Molecular dynamics simulations of Polymer-Bonded Explosives (PBXs): Modeling, mechanical properties and their dependence on temperatures and concentrations of binders

Two models, i.e. "covering" and "cutting" models, for the polymer-bonded explosives (PBXs) were proposed for different researching aspects. Used for choosing polymeric binders, the "covering" models are mainly applied to find the relations of temperatures and concentrations respectively with elastic properties of the PBXs. The "cutting" model is especially used to describe the highly anisotropic behavior of 1,3,5-triamino-2,4,6-trinitrobenzene crystals (TATB). These models were realized by using molecular dynamics methods. It is found that the ductility of crystalline TATB can be effectively improved by blending fluorine-containing polymers in small amounts. The moduli for the PBXs decrease with increase in temperature and concentration of binders. Different crystalline surfaces interacting with the same polymer binder have different modulus-decreasing effects due to the highly anisotropic behavior of TATB. The modulus-decreasing effect for different crystalline surfaces ranking order is (010) ≈ (100) > (001).