Synergistic Hydrogen-Bonded and Ion-Conductive Binders for Robust, Safe HMX Composites

Developing binders that integrate excellent mechanical properties with electrical conductivity is critical to meeting the urgent demand for improved safety and reduced vulnerability in HMX-based energetic composites. Herein, a synergistically enhanced elastomer, termed AAP, was fabricated via ultraviolet-initiated free radical polymerization. The synthesis involved a polymerizable deep eutectic solvent designed from acrylic acid and acryloyloxyethyltrimethylammonium chloride, further reinforced by phytic acid, which provides high hydrogen-bond density, and the cross-linker polyethylene glycol diacrylate. The resulting elastomer features a dynamic hydrogen-bond network and efficient ion-conductive pathways. Notably, the optimized sample, AAP-2, exhibits outstanding comprehensive properties, including a tensile strength of 9.38 MPa, an elongation at break of 796.55%, a toughness of 48.41 MJ·m–3, intrinsic self-healing capability, high adhesion strength with aluminum, and an electrical conductivity of 8.179 × 10–5 S/m. When employed as a binder, AAP demonstrated excellent compatibility with HMX. The H50-AAP50 composite maintained high toughness while achieving superior tensile strength compared to traditional HTPB-based composites. More importantly, owing to its intrinsic ionic conductivity, the AAP-2 coating significantly mitigated the mechanical and electrostatic sensitivities of HMX. Consequently, the electrostatic spark sensitivity threshold of the H90AAP10 sample increased markedly from 0.54 J for raw HMX to 3.6 J. This work offers new insights into the design of multifunctional binders for the construction of high-performance, safe, and low-vulnerability energetic composites.