Bio-inspired hydrophobic copper stearate coating to reduce the moisture absorption of fine-grained ammonium perchlorate and improve safety and thermal decomposition performance

Inspired by the superhydrophobic phenomenon in nature, multifunctional fine-grained ammonium perchlorate (F-AP)@copper stearate (CS) core-shell structure composite particles were designed by the in-situ liquid deposition method. Scanning electron microscopy (SEM) characterization proved that raw AP was refined, and a series of in-depth characterizations proved that the core-shell structure of F-AP@CS was prepared. Due to the core-shell F-AP@CS bionic hydrophobic structure and low surface energy, when the CS content is 5%, the moisture absorption rate was reduced from 0.54% to 0.03% within 72 h, and the water contact angle was increased to 126.6°. At room temperature, the safety performance of F-AP is effectively improved because of the barrier effect and melting heat absorption of the CS shell, the impact sensitivity (H50) of F-AP@CS (wt = 5%) was increased from 27.2 cm to 54.2 cm, and the friction sensitivity was reduced from 96% to 0%. As the temperature rises, CS will decompose into CuO with extremely high catalytic activity at 267 °C, the high temperature decomposition peak of F-AP@CS (wt = 5%) was advanced from 423.3 °C to about 305.9 °C, and speculate the mechanism of CS catalyzing the decomposition of AP.