New insight into dynamic mechanical relaxation in N-butyl-N-(2-nitroxy-ethyl) nitramine plasticized nitrocellulose through molecular dynamic simulations

We performed dynamic mechanical analysis (DMA) on nitrocellulose (NC) plasticized by an insensitive plasticizer N-butyl-N-(2-nitroxy-ethyl)nitramine (Bu-NENA). NC/Bu-NENA blend shows two relaxation processes in the temperature ranges of − 50 to 40 °C and 30 ~ °C, their variations with deformation frequencies were studied. To explore further effect relaxation, binary mixture model was constructed, molecular simulations conducted. The simulated mean square displacements (MSD) show abrupt increase range which are consistent those observed DMA curves. Moreover, free volume (Vfree) torsion energy obtained from exhibit distinct at above respectively, reflecting sudden enhancements mobility polymer chain elements rotation bonds. Furthermore, radial distribution function (RDF) associated intermolecular interactions reveals that intensities both hydrogen bond van der Waals forces decrease temperature, is responsible for storage modulus high temperature. These computational experimental studies reveal guidance strengthening NC base propellants broad range.