Molecular Dynamics Simulation of Binding Energies, Mechanical Properties and Energetic Performance of the RDX/BAMO Propellant

Molecular dynamics (MD) simulations were performed to investigate the well-known energetic material cyclotrimethylene trinitramine (RDX) crystal, 3,3'-bis-azidomethyl-oxetane (BAMO) and the RDX/BAMO propellant. The results show that the binding energies of RDX with BAMO on different crystalline surfaces change as follows: (010)>(100)>(001). The interactions between RDX and BAMO were analyzed by pair correlation functions g(r). The mechanical properties of the RDX/BAMO propellant, such as the elastic coefficients, modulus, Cauchy pressure, and Poisson's ratio, were obtained. We find that the mechanical properties are effectively improved by adding some BAMO polymer and the overall effect of BAMO on the three crystalline surfaces of RDX changes as follows: (100)>(001)>(010). The energetic performance of the RDX/BAMO propellant was also calculated and the results show that compared with the pure RDX crystal, the standard theoretical specific impulse (I-sp) of the RDX/BAMO propellant decreases but it is still superior to that of the double base propellant.