Bridging Al-PTFE enhances energy output and mechanical properties of LLM-105

The energy release of energetic composites is severely limited by the inert alumina (Al 2 O 3 ) layer on the surface of aluminum (Al). Polytetrafluoroethylene (PTFE) could eliminate Al 2 O 3 layer due to its highly electronegativity and oxidability of fluorine. However, adding PTFE particles would weaken interfacial interactions resulted in poor mechanical properties and interfacial exothermic reaction. Herein, a bridging Al-PTFE as fuel and interfacial reinforcing agent was added and used to prepare LLM-105/Al-PTFE microspheres, achieving both high energy output and excellent mechanical properties. The energy release and combustion reaction performance of LLM-105/Al-PTFE microspheres are significantly improved due to high reaction heat and increased interfacial reaction area of Al-PTFE. The maximum pressure and pressurization rate of LLM-105/Al-PTFE microspheres are 164.06 kPa and 29.88 kPa/s, respectively, which are 40.11% and 16.67% higher than those of physical mixed samples. Furthermore, the tensile strength and compressive strength of LLM-105/Al-PTFE microspheres are 100.40% and 26.47% higher than those of LLM-105/Al. This work provides a new approach to improve the energy release and mechanical properties for energetic composite.