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The development of a facile method for improvement of interface interaction between rigid particles and coating polymer is of great importance for energetic composite materials, especially for military purpose. In this paper, energetic composites with spherical morphology, toughness property and low sensitivity are firstly fabricated by using Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) as core material and thermoplastic polyester-ether elastomer (TPEE) as shell material via an emulsion solvent evaporation (ESV) method. From the morphology and structure characteristic of as-prepared energetic microspheres, it is found that the HMX@TPEE energetic microspheres have uniform spherical morphologies, narrow size distribution and honeycomb coating structure under the circumstance of compound emulsifiers and appropriate core-shell ratio. The good toughness of HMX@TPEE microspheres in Brazilian test and dynamic mechanical analysis (DMA) demonstrates a new route to enhance interface interaction between HMX particles and TPEE matrix. Moreover, because of the favorable energy-decentralizing property of this exotic honeycomb structure, the sensitivity of HMX@TPEE microspheres measured by BAM impact sensitivity instrument can be markedly decreased and the impact energy ( E li ) can be improved from 3.5 J to 8.0 J at the HMX/TPEE ratio of 5/1. This fabrication of HMX@TPEE microspheres with adjustable coating content via a facile ESV process might provide a promising approach for HMX based energetic composites to enhance the safety and toughness properties when used in advanced weapon system. [ABSTRACT FROM AUTHOR]

The interfacial strength usually plays a key role for exhibiting great effects on mechanical performances. In this work, typical energetic crystal 1,3,5-triamino-2,4,6-trintrobenzene (TATB) was firmly coated by the strong adhesion of polydopamine (PDA), then two HBPs with fatty and aromatic structure were grafted onto the surface of TATB, by using the hydroxyl groups of the PDA layer as secondary reaction platform. Four highly-loaded polymer based energetic composites (solid loading was 95%) were prepared with fluoropolymer binders as substrate. The results showed that the surface of grafted samples with 0.5 wt% HBP was more easily wetted by non-polar liquid. Improved storage modulus and creep resistance properties were exhibited in polymer bonded explosives (PBXs). The static mechanical properties of tensile and compressive strength were increased significantly by 26.5% and 19.8%, respectively, due to the strong interfacial reinforcement of HBPs. • Successfully grafting hyperbranched polyester to energetic crystal for the first time. • Mechanical properties of PBX effectively enhanced by hyperbranched polyester grafting. • Interfacial reinforcement strategy can be extended to other highly loaded composites. [ABSTRACT FROM AUTHOR]