Litchi-like Core-Shell HMX@HPW@PDA Microparticles for Polymer-Bonded Energetic Composites with Low Sensitivity and High Mechanical Properties

The reduction of interfacial interaction and the deterioration of mechanical properties by the introduction of the indispensable paraffin wax is a long-standing problem. To address it, a novel litchi-like core-shell 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX)@paraffin wax@polydopamine (PDA) structure was constructed with a new high melting point paraffin wax (HPW, 101.9 °C) as the inner shell and the bio-inspired strong adhesive PDA as the exterior shell. The evolution of element states on the surface of energetic microcapsules conducted by X-ray photoelectron spectroscopy (XPS) indicated that the successful introduction of paraffin wax and PDA to form the core@double shell structure. Compared with the core@double shell particles based on the conventional low melting point paraffin wax (LPW, 69.8 °C), the HMX@HPW@PDA particles demonstrated a 120% increase of impact energy EBAM from 5 J (raw HMX) to 11 J by Bundesanstalt fur Materialprufung (BAM) method. Attributed to the stronger interfacial interaction,...