Research Progress on Mechanical Enhancement of Polymer-Based Energetic Composites by Coating of the Crystalline Fillers

In the field of energetic materials (EMs), the energy level needs to be boosted by increasing the solid loading of energetic composites. Nevertheless, the weak interfacial strength between energetic crystals and binders adversely affects the mechanical properties of these high solid-content energetic composites, thereby limiting their practical applications. A large number of papers have been published on the topic of ameliorating weak interfacial interaction, which has been summarized in this review. The coating technique has been widely implemented in the modification of energetic crystals including nitramine explosives and insensitive energetic compounds with amino groups for improved safety and mechanical properties. It has been demonstrated that the interfacial interactions between energetic crystals and binders can be significantly enhanced through this technique, resulting in much better mechanical properties. This review offers a detailed summary of the preparation techniques, fundamental properties of coated energetic crystals, and the mechanical parameters of the corresponding energetic composites. The preparation methods for coatings include grinding, spraying, and in situ coating.