Thermodynamic, transport and viscoelastic properties of PBX-9501 binder: a molecular dynamics simulation study

Atomistic molecular dynamics simulations were performed on a low molecular weight nitroplasticized Estane® mixture representative of the binder used in PBX-9501. Pressurevolume-temperature (PVT) behavior over a wide range of pressure and temperatures above the order-disorder temperature (ODT) of Estane was determined and represented with the empirical Tait and Sun equations-of-state. The effect of temperature, pressure and plasticization on transport properties of the mixture was also examined. A combination of molecular dynamics simulations and theoretical reptation models was used to predict the shear stress relaxation modulus G(t) of PBX-9501 binder at 473 K and 1 atm pressure. Data obtained from simulations of the model PBX-9501 binder presented here can be utilized to predict the temperature and pressure dependence of the shear stress relaxation modulus for temperatures above the ODT.