Multiscale simulation of effects of nitroglycerin plasticizer on morphology and mechanical properties of nitrocellulose-based propellants

Nitrocellulose (NC) blended with nitroglycerin (NG) forms a key energetic polymer system, but the interplay between composition and chain length of NC on its microstructure and mechanics remains unclear. This work uses a multiscale simulation approach combining MesoDyn and lattice spring model (LSM) to systematically study how NC chain length and NC/NG ratio influence morphology evolution, interfacial characteristics, and mechanical behavior. The results show that increasing NC content strengthens phase separation and reduces the interfacial area, leading to the formation of a continuous and rigid NC network. Longer NC chains enhance network connectivity, which facilitates stress transfer and improves mechanical integrity. When interfacial strength varies, the stress distribution becomes more uniform. Consequently, both Young's modulus and fracture strain increase with NC content, indicating simultaneous enhancement of stiffness and toughness. The study highlights that precise tuning of chain length and composition is essential to optimize structure–property relationships in NC/NG blends, offering valuable guidance for designing high-performance energetic polymer composites. • Multiscale simulations reveal how NC chain length and NC/NG ratio govern morphology and mechanics. • Higher NC content and longer chains promote rigid network formation and efficient stress transfer. • Simultaneous improvement in stiffness and toughness achieved by tuning composition and chain length.