Theoretical Prediction on Properties of 3,4-Bisnitrofurazanfuroxan (DNTF) Crystal and its Polymer Bonded Explosives (PBXs) Through Molecular Dynamics (MD) Simulation

Context 3,4-Bisnitrofurazanfuroxan (DNTF) is a typical high energy density compound (HEDC), it has high crystal density and detonation parameters, but also high mechanical sensitivity. To decrease its mechanical sensitivity, the DNTF based polymer bonded explosives (PBXs) was designed. The pure DNTF crystal and PBXs models were established. The stability, sensitivity, detonation performance and mechanical properties of DNTF crystal and PBXs models were predicted. Results show that PBXs models containing fluorine rubber (F 2311 ) and fluorine resin (F 2314 ) have higher binding energy, meaning that DNTF/F 2311 and DNTF/F 2314 is relatively more stable. PBXs models have higher value of cohesive energy density (CED) than pure DNTF crystal, DNTF/F 2311 and DNTF/F 2314 have the highest value of CED, implying that the sensitivity of PBXs is effectively decreased, DNTF/F 2311 and DNTF/F 2314 is more insensitive. PBXs have lower crystal density and detonation parameters than DNTF, the energy density is declined, DNTF/F 2314 has higher energetic performance than other PBXs. Compared with pure DNTF crystal, engineering moduli (tensile modulus, shear modulus, bulk modulus) of PBXs models are obviously decreased, but Cauchy pressure is increased, implying that the mechanical properties of PBXs is superior to pure DNTF component, the PBXs containing F 2311 or F 2314 have more preferable mechanical properties. Consequently, DNTF/F 2311 and DNTF/F 2314 have the best comprehensive properties and is more attractive among the designed PBXs, indicating that F 2311 and F 2314 are more advantageous and promising in ameliorating properties of DNTF. Methods The properties of DNTF crystal and PBXs models were predicted through molecular dynamics (MD) method under Materials Studio 7.0 package. The MD simulation was performed with isothermal-constant volume (NVT) ensemble, and the force field was chosen as COMPASS force field. The temperature was set as 295 K, the time step was 1 fs and the total MD simulation time was 2 ns.