Molecular Dynamics Simulations for Effects of Fluoropolymer Binder Content in CL-20/TNT Based Polymer-Bonded Explosives

Abstract

In order to better understand the role of binder content, molecular dynamics (MD) simulations were performed to study the interfacial interactions, sensitivity and mechanical properties of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/2,4,6-trinitrotoluene (CL-20/TNT) based polymer-bonded explosives (PBXs) with fluorine rubber F2311. The binding energy between CL-20/TNT co-crystal (1 0 0) surface and F2311, pair correlation function, the maximum bond length of the N–NO2 trigger bond, and the mechanical properties of the PBXs were reported. From the calculated binding energy, it was found that binding energy increases with increasing F2311 content. Additionally, according to the results of pair correlation function, it turns out that H–O hydrogen bonds and H–F hydrogen bonds exist between F2311 molecules and the molecules in CL-20/TNT. The length of trigger bond in CL-20/TNT were adopted as theoretical criterion of sensitivity. The maximum bond length of the N–NO2 trigger bond decreased very significantly when the F2311 content increased from 0 to 9.2%. This indicated increasing F2311 content can reduce sensitivity and improve thermal stability. However, the maximum bond length of the N–NO2 trigger bond remained essentially unchanged when the F2311 content was further increased. Additionally, the calculated mechanical data indicated that with the increase in F2311 content, the rigidity of CL-20/TNT based PBXs was decrease, the toughness was improved.

Effects of Temperature on Novel Molecular Perovskite Energetic Material (C6H14N2)[NH4(ClO4)3]: A Molecular Dynamics Simulation

“…The binding energy denotes the degree of interaction among the different components and can reflect the thermal stability of the system. 24 A higher binding energy indicates a stronger interaction between the components and therefore a more stable system. It is clearly seen that the E bind value of the compounds gradually decreases with an increase in temperature, which demonstrates that the thermodynamic stability of the system decreases.…”

“…The binding energy denotes the degree of interaction among the different components and can reflect the thermal stability of the system. 24 A higher binding energy indicates a stronger The corresponding deviations are given in parentheses. interaction between the components and therefore a more stable system.…”

Intermolecular Vibration Energy Transfer Process in Two CL-20-Based Cocrystals Theoretically Revealed by Two-Dimensional Infrared Spectra

“…Based on the principle of the smallest bond order (PSBO) calculated via quantum chemistry, more sensitive energetic compounds usually contain a smaller bond order of trigger bond in molecules, and it is known that the CL-20 component in TNT/CL-20 decomposes earlier in detonation because CL-20 is more sensitive [ 24 , 53 ]. Therefore, the stability of the N-NO 2 bond in CL-20 as a trigger bond was investigated using the Mayer BOD approach ( Table 2 ) [ 44 , 54 ].…”

“…Hübner et al characterized a nanoscale HMX/CL-20 cocrystal prepared by spray flash evaporation through tip-enhanced Raman spectroscopy and proposed that the HMX surface finishing might contribute to the impact sensitivity of HMX/CL-20 [ 19 ]. The major part of the theoretical approaches consisted of classical molecular dynamic simulations of intermolecular interactions, vibrational spectra and detonation performance, where the atomic interactions were based on sophisticated force fields [ 20 , 21 , 22 , 23 , 24 ]. All these works demonstrated that energetic cocrystals created a distinct solid-state arrangement at the molecular level and the intermolecular non-covalent interactions were the main driving forces for the cocrystal formation [ 25 , 26 , 27 ].…”

Injection moldable, self-healable, and recyclable rubber-bonded NdFeB magnets with the magnetic particulates content up to 90 wt%

“…Along with the incorporation of fluorine to HTPB-DA, the interfacial interaction of the composite is somewhat decreased, so that the Wa/γmf value of NdFeB-M/HTPB-F3-DA is decreased from 7.11 to 4.69 [39]. Meantime, the spreading coefficient of the system is improved from 21.86 mJ m -2 to 24.21 mJ m -2 .…”