Preparation and properties of safer high-energy HMX/F2602/FGO composite energetic materials

High-energy composite microspheres are fabricated using coaxial flow-focusing microdroplet technology. • Fluorinated additives enhance the thermal stability and combustion performance of HMX-based microspheres. • Comprehensive analysis of microstructure, chemical structure, and thermal decomposition behavior. • The microspheres exhibit excellent mechanical safety and controlled combustion characteristics. High-energy composite microspheres based on HMX were fabricated via coaxial flow-focused microdroplet technology to elucidate the role of functional components in regulating safety and energetic performance. Four composite systems, HMX/F2602, HMX/F2602/FGO, HMX/F2602/PTFE, and HMX/F2602/PVDF, were comparatively investigated using HMX/F2602 as the reference. The incorporation of fluorinated graphene oxide (FGO) resulted in microspheres with a well-defined spherical morphology, dense surfaces, high sphericity, and a narrow particle size distribution, with an average diameter of approximately 470 μm. XRD and FTIR analyses confirmed that all composites preserved the intrinsic chemical structure of HMX without detectable chemical transformation. Thermal analysis showed that HMX/F2602/FGO exhibited moderated decomposition behavior, achieving a favorable balance between thermal stability and reactivity, with an apparent activation energy intermediate among the studied systems and a reduced peak decomposition temperature. Mechanical sensitivity evaluation demonstrated significantly increased critical impact and friction thresholds compared with the other composites. Combustion tests further revealed enhanced combustion stability and increased luminous intensity, a shortened ignition delay time of 43.31 ms, and an extended combustion duration of 2.11 s. Overall, the incorporation of the two-dimensional FGO network provides an effective structural strategy to simultaneously enhance the mechanical safety and stabilize the deflagration behavior of HMX-based composites, offering valuable insights for the microstructural design of advanced energetic materials. In this study，HMX-based composite microspheres were prepared via coaxial flow-focused microdroplet technology. The incorporation of fluorinated graphene oxide (FGO) produced uniform microspheres with dense surfaces and narrow particle size distribution (∼470 μm) while preserving the intrinsic structure of HMX. The HMX/F/FGO system exhibited moderated thermal decomposition, enhanced mechanical safety, shortened ignition delay (43.31 ms), and prolonged combustion duration (2.11 s), demonstrating synergistic optimization of safety and energetic performance. Download: Download high-res image (225KB) Download: Download full-size image