Research of the effect of hydrated salt-based phase change composites on the safety properties of HMX-based PBX

To explore a new functional explosive with improved safety performance, this study synthesized a hydrated salt-based phase change composite (PCC) using magnesium sulfate heptahydrate and ammonium aluminum sulfate dodecahydrate as raw materials. Additionally, HMX/F2602/PCC composite microspheres were prepared via spray drying. The HMX/F2602/PCC composite microspheres were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and impact sensitivity testing. The results indicate that HMX/F2602/PCC composite microspheres exhibit superior morphology and safety, compared with HMX/F2602 composite microspheres. Under the premise that the thermal sensitivity of HMX-based PBX remains essentially unchanged, the apparent activation energy decreases by 34.46 kJ/mol and 58.85 kJ/mol when the PCC content is 1% and 1.5%, respectively. Moreover, compared with HMX/F2602 composite microspheres, the characteristic drop heights of HMX/F2602/PCC composite microspheres with three different mass ratios increase by 5.72 cm, 10.55 cm, and 14.68 cm, respectively. Correspondingly, their impact sensitivity is significantly reduced, and their safety performance is notably improved.