Design of conductive polymer coating layer for effective desensitization of energetic materials

Safety performance under external stimuli plays a crucial role for energetic materials. Therefore, desensitization of high explosive arouses widespread research interests in the field of energetic materials. Nevertheless, synergistically reducing impact and electrostatic spark sensitivities of 1,3,5,7-tetranittro-1,3,5,7-tetrazocane (HMX) remains challenging. Herein, a novel strategy concerning conductive polymer coating was proposed to solve this issue. Theoretically, the polypyrrole (PPy) can form a complete shell and strong interaction with HMX crystals. The HMX@PPy composite has been successfully achieved by in-situ polymerization, exhibiting superior sensitivities (impact: from 7 J to 27.5 J and electrostatic spark: from 0.4 J to 1.68 J) among reported HMX-based energetic materials. In addition, the thermal phase stability of HMX can also be visibly improved with sluggish phase-transition kinetics by introducing PPy coating. The current study provides a design concept for high energy explosives with low sensitivity and improved comprehensive performances.