Structure–property relationships of civilian nitrocellulose/RDX energetic composites: combining experiments and MD simulation

The trade-off between energetic performance and mechanical integrity remains a central challenge in the development of advanced solid propellants. In this work, a high-viscosity civilian nitrocellulose (CNC) was employed as the binder to formulate CNC/RDX-based gun propellants, and their thermal decomposition, impact resistance, combustion behavior, and structural stability were systematically investigated through thermal analysis, impact testing, closed-bomb experiments, and molecular dynamics simulations. Kinetic analyses based on iso-conversional and linear methods reveal that the incorporation of RDX increases the apparent activation energy, indicating an enhancement in thermal stability. Impact tests demonstrate a non-monotonic dependence of shock resistance on RDX content, with the 5 wt% RDX formulation exhibiting the highest impact strength, corresponding to a 69.7% improvement at low temperature relative to the CNC-based propellant. Closed-bomb results show that all CNC/RDX propellants burn steadily, while the impetus increases progressively with increasing RDX loading. Molecular dynamics simulations further indicate that RDX alters the spatial packing and intermolecular interaction network of the propellant matrix by strengthening non-bonded interactions between CNC and RDX, accompanied by an increase in thermal conductivity.