Copper Stearate-Coated Dap-4 Core–Shell Composites for Enhanced Safety and Thermal Decomposition Performance

Abstract

In this study, DAP-4@copper stearate (CS) core–shell composites were fabricated by an in situ synthesis and liquid deposition using CS as the catalyst. In addition, a comprehensive characterization was conducted on the morphology, structure, thermal decomposition, and safety performance of the acquired samples. The results revealed that DAP-4@CS composites with a complete, compact core–shell structure. During thermal analysis experiments, DAP-4@CS (5, 10, 15, and 20 wt%) resulted in a reduction in the thermal decomposition peak temperatures (Tp) by 37.93°C, 57.73°C, 70.93°C, and 76.47°C respectively when compared with DAP-4, and their corresponding activation energy values decreased by 90.06, 108.31, 90, and 90.31 kJ/mol. Notably, the DAP-4@CS composites with 5 wt% and 10 wt% CS exhibited increased heat release by 1312.86 and 1546.8 J/g, respectively. The H50 value for DAP-4 increased from an initial value of 44.67 cm to an improved value of 64.57 cm, while its friction sensitivity increased from 30 N to 40 N during safety experiments. Moreover, we propose the principle of thermal decomposition catalysis and desensitization of CS for DAP-4. The aforementioned findings offer valuable insights to further enhance the advancement of composite solid propellants based on DAP-4.

Keywords: DAP-4, thermal decomposition, safety, copper stearate, core-shell structure