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 35.22, 55.02, 68.22 and 73.76 °C respectively when compared with DAP-4, and their corresponding activation energy values decreased by 61.22, 87.3, 63.62, and 69.54 kJ/mol. Notably, the DAP-4@CS composites with 5 wt% and 10 wt% CS exhibited increased heat release by 1291.03 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 above research results provide a new solution to the contradictions and obstacles in the application of DAP-4 as an oxidizer in fuel.