Ultrasonic approach to the synthesis of HMX@TATB core–shell microparticles with improved mechanical sensitivity

•HMX@TATB core–shell microparticles are synthesized via an ultrasonic route.•The microparticles possess a monodisperse size and compact shell structure.•The perfect core–shell composites exhibit improved mechanical sensitivity.•This ultrasonic strategy can be extended for coating TATB on different core.

To improve the safety of sensitive explosive HMX while maintaining explosion performance, a moderately powerful but insensitive explosive TATB was used to coat HMX microparticles via a facile ultrasonic method. By using Estane as surface modifier and nano-sized TATB as the shell layer, the HMX@TATB core–shell microparticles with a monodisperse size and compact shell structure were successfully constructed. Both scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) results confirmed the formation of perfect core–shell structured composites. Based on a systematic and comparative study of the effect of experimental conditions, a possible formation mechanism of core–shell structure was proposed in detail. Moreover, the perfect core–shell HMX@TATB microparticles exhibited a unique thermal behavior and significantly improved mechanical sensitivity compared with that of the physical mixture.