Innovative Reactive Structural Materials: Rigid Polymers for Enhanced Ammunition Performance

Modern-day ammunition typically contains only about 30 wt% of payloads such as RDX-based explosives, while the majority of the mass is made up of structural materials like metals (e.g., steel and aluminum) that do not contribute to the energy output. This composition underscores a significant potential for enhancement through the use of reactive structural materials (RSMs). These advanced materials are engineered to fulfill dual roles: maintaining structural integrity and releasing chemical energy upon activation. Rigid polymers with glass transition temperatures higher than operational temperatures are emerging as promising candidates to replace heavy, less effective, and metal-based materials (e.g., alloys, thermites). In line with this vision, we present the synthesis and characterization of a resorcinol 2,4-paranitroaniline-based benzoxazine (RE-dnph) energetic polymer, utilizing resorcinol as a green phenolic source. The energetic properties of this polymer were thoroughly assessed. The newly developed polymer demonstrated promising energetic performance with ignition temperatures ranging from 260°C to 265°C, and a combustion heat release of 23.33 kJ·g −1 during ignition. Differential scanning calorimetry-thermogravimetric analysis (DSC-TGA) analysis results indicated that these polymers are highly suitable for use as RSMs due to their combination of rigidity at operational temperatures and exceptional energetic performance.