Preparation of pCL-20/PTFE-Al composites for sensibility reduction and combustion improvement

The high sensitivity of high explosive hexanitrohexaazaisowurtzitane (CL-20) limits its applicability, and the performance optimization brought by the synergistic effect between nanothermite and CL-20 is expected to expand its application prospects. In this study, polydopamine (PDA) was introduced to modify CL-20 (denoted as pCL-20), and a quasi-core/shell pCL-20/polytetrafluoroethylene-aluminum (pCL-20/PTFE-Al) composite was successfully prepared by ultrasonic-assisted composite method. The performance characterization results demonstrate that the composite exhibits significantly better decomposition heat release than the mixed sample, a reduction in combustion time from 408 ms to 268 ms, a more stable combustion flame, and more focused energy release. At the same time, the comparison of composite combustion with different condition variables reflects the combustion advantages of the selected proportional conditions in this study. The characteristic drop height (H50) increased from 24.05 cm to 42.15 cm, the explosive percentage of friction sensitivity reduced from 100 % to 70 %, and the sensitivity of the composite sample decreased significantly when compared to the raw CL-20. It improves the combustion performance while reducing the sensitivity, thereby enhancing the application potential and providing a reference for the high-energy desensitization of energetic materials. •The quasi-core-shell composite was successfully prepared.•The issue of poor dispersion and particle aggregation is somewhat resolved.•Polytetrafluoroethylene breaks alumina shell barrier. Two-phase loss is reduced.•The combustion performance is improved and the mechanical sensitivity is reduced.