Polynitromethyl high-energy materials with a tricyclic furoxan-oxadiazole scaffold: Synthesis, stability, and detonation performance

Polynitromethyl explosives exhibit outstanding detonation performance, yet their application is significantly hindered by safety concerns. Thus, enhancing the stability of polynitromethyl high-energy density materials (HEDMs) while maintaining high energy levels is of urgent importance. In this study, a novel tricyclic scaffold combining furoxan and 1,2,4-oxadiazole was successfully constructed. Two new HEDMs, 3,4-bis(5-fluorodinitromethyl-1,2,4-oxadiazol-3-yl)furoxan ( BOFN-4 ) and 3,4-bis(5-trinitromethyl-1,2,4-oxadiazol-3-yl)furoxan ( BOTN-6 ), were designed and synthesized by introducing a polynitromethyl energetic group for the first time. Experimental tests and theoretical calculations revealed that BOFN-4 possesses a higher thermal decomposition temperature ( T d peak: 193 °C) and lower mechanical sensitivity (IS: 8 J, FS:252 N) compared to most reported fluorodinitromethyl-functionalized energetic compounds, while also exhibiting high density ( ρ : 1.92 g·cm −3 , 296 K). As a zero-oxygen balance explosive, BOTN-6 demonstrated 1.3 times the destructive performance of octogen ( HMX ) in plasma initiation experiments. These results indicate that the introduction of a tricyclic furoxan-isofurazan scaffold is an effective strategy to overcome the thermal stability and sensitivity limitations of polynitromethyl HEDMs, without compromising their energy levels.