Molecular Dynamics Simulation Study On RDX/Fluoropolymer And PEG/Nitrate Composite

Highly explosive RDX is a typical six-membered heterocyclic nitroamine.It is widely used as a compound explosive with good comprehensive property. Molecular dynamics simulations were employed to investigate RDX crystals and RDX-based PBXs using NPT ensemble with COMPASS force field. The thermodynamic equilibrium judgement is based on the the fluctuation of temperature and potential energy within10%. First of all, we calculate the mechanical properties of the supercell2×2×3RDX (100) crystal at295K and under different pressure (0GPa,2GPa,4GPa,6GPa,8GPa), which consist of elasticity, tensile modulus, Poisson’s ratio, bulk modulus,shear modulus and so on.Then, Molecular dynamics simulation is applied to study the structure and energy properties of RDX-based PBXs in the same conditions.This paper also investigates the PEG and PEG/nitro ester system with MD simulations. Nitric acid ester plasticized polyether (NEPE) propellant has a good advantage of high energy and low temperature mechanical properties, which has the characteristic of modified double-base propellant and composite propellant. Though PEG as the binder in the NEPE propellan has the low content(mass fraction6%～8%)but it plays an important role in the mechanical properties of the propellant.Our system are based on the PEG as the binder, NG and BTTN as the plasticizer. Molecular dynamics simulation simulates the mixed system of PEG and nitrate at different temperatures and different concentrations. After equilibration run we can achieve particle equilibrium trajectory at atomic level, and then analysis the component interaction mechanism and discover the nature of the interaction in the hybrid system. Finally, we can draw the mixing energy and basic thermodynamic parameter.