Reactive molecular dynamics study on the thermal decomposition reaction of a triple-base solid propellant

The study of the combustion property of newly designed propellant by means of computational simulation is an efficient pathway for assessment and could avoid exposure to hazardous chemicals. An RDX-modified triple-base solid propellant formula was proposed in this study. Reactive molecular dynamics simulations employing ReaxFF-lg force field were performed to explore the thermal decomposition property of the propellant for a variety of temperatures. The reaction kinetics of the system and major ingredients were analyzed, and the apparent decomposition activation energies were calculated. The population of decomposition intermediates and products is thoroughly investigated. H₂O is consumed at high temperatures indicating a water-gas reaction that could reduce carbon clusters during the combustion of solid propellant. The water-gas reaction, as well as the population of H₂ at high temperature, points out the way of adjusting the formula of the propellant, which is adding fuel and oxidizer to improve combustion temperature and oxygen balance.