The thermal decomposition mechanism and kinetic study of TNBP based on molecular dynamics.

context2,8-Bis (2,4,6-trinitrophenyl)-5,11-dioxo-2,4,6,8,10,12-hexacyclo[7.3.0.03,7]dodecane-1(12),3,6,9-tetraene (TNBP) is a new thermally stable explosive renowned for its exceptional detonation performance and thermal stability, making it highly valuable for applications in supersonic weapons, aerospace engineering, and ultra-deep well perforation. This study utilizes reactive molecular dynamics simulations to elucidate the thermal decomposition mechanism and kinetics of TNBP. Under both non-isothermal and isothermal conditions, the initial decomposition stages involve key reactions such as intermolecular oxygen transfer, dimerization, and NO dissociation. The primary decomposition products include small molecules like NO

methodsMolecular dynamics simulations of the thermal decomposition behavior of TNBP were conducted using the Large-scale Atomic/Molecular Parallel Simulator (LAMMPS) in conjunction with the ReaxFF/lg reaction force field. First, a 2 × 2 × 1 supercell model was constructed based on X-ray diffraction crystal data. To obtain a reasonable initial equilibrium configuration, the system underwent 5 ps of geometric optimization under NPT conditions (300 K, 1 atm) with a time step of 0.1 fs and a temperature damping coefficient of 10 fs. The applicability of the ReaxFF/lg force field in describing the TNBP system was verified by comparing crystal parameters with the interatomic radial distribution function. To investigate the impact of elevated temperatures on TNBP thermal decomposition, two heating simulation protocols were employed: First, the system was heated from 300 to 2700 K at a rate of 12 K·ps