Molecular dynamics (MD) simulations were conducted for a CL-20/DNB (2, 4, 6, 8, 10, 12-hexanitro-2, 4, 6, 8, 10, 12-hexaazaisowurtzitane/1, 3-dinitrobenzene) co-crystal based PBX (Polymer-bonded explosive) with HTPB (hydroxyl-terminated polybutadiene). The binding energies, pair correlation functions and mechanical properties of the PBX were reported. From the calculated binding energy (E bind), it was found that the order of the binding energies between the crystalline surfaces (1 0 0), (0 1 0) and (0 0 1) and HTPB is (1 0 0) > (0 0 1) > (0 1 0). And it was also shown that the interactions between the crystalline surfaces and HTPB originate mainly from vdW energies. The pair correlation function revealed that H···O hydrogen bonds exist on the interfaces between the crystalline surfaces and HTPB. From the calculated mechanical data, the co-crystal/HTPB was inferred that the PBX has a higher buffer for external stimuli and reduces the formation probability of hot spots.

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The decomposition mechanism of 3-methyl-2,6-dinitrophenol (MDNP) was simulated by reaction molecular dynamics using ReaxFF force field. The evolution of some main products with time at different heating rates (10, 15 and 20 K·ps-1) were obtained as well. The simulation outcomes reveal that with the elevation of the heating rate, the shorter the time required for the system to reach equilibrium, and the more products are produced. At three heating rates, the main intermediate products are C7H7O5N2, C7H6O4N2, C7H5O5N2, C7H5O4N2, HON, NO, NO2 and the primary final products are N2, CO2, H2O, H2, NH3, amongst which C7H5O5N2 is the first produced intermediate product and H2O is the first produced final product with the biggest abundance. The intermediate products first increase and then decrease to zero. Moreover, the primary chemistry reactions in the MDNP pyrolysis are acquired by ReaxFF MD simulations.