Abstract: Nano-SrCO₃ was prepared by ultrasonic-assisted co-precipitation, and nano-SrCO₃/AP composite particles were prepared by solvent-nonsolvent method. The morphology, particle size, crystal type and composite effect of nano-SrCO₃/AP composite particles were characterized by transmissive electron microscope (TEM), scanning electron microscope (SEM) and X-ray powder diffractometer (XRD). The impact sensitivities of SrCO₃/AP composites with pure AP and different contents were tested. Thermal decomposition properties of nano-SrCO₃/AP composite particles and a simple mixture of nano-SrCO₃ and AP were analyzed by using DSC. The nano-SrCO₃/AP composite particles were calcined in a muffle furnace at 350 ℃ and 500 ℃, respectively, for 1 h. The calcined products were characterized by XRD, and the action mechanism of nano-SrCO₃ was studied. The results show that nano-SrCO₃ prepared by ultrasonic-assisted co-precipitation is spherical with a particle size of about 60 nm, and its crystalline form is orthorhombic. In the nano-SrCO₃/AP composite particles prepared by solvent-nonsolvent method, nano-SrCO₃ is uniformly distributed on the surface of AP. The impact sensitivity of AP increases with the addition of nano-SrCO₃. Nano-SrCO₃ added in two different ways can increase the decomposition peak temperature of AP at high temperature, but has no effect on the decomposition of AP at low temperature. Compared with the simple mixture of nano-SrCO₃ and AP, the peak decomposition temperature of AP in nano-SrCO₃/AP composite particles is increased by 6.02 ℃. It is proved that the negative catalytic effect of nano-SrCO₃ on AP decomposition at high temperature can be improved by compounding nano-SrCO₃ with AP. Key

Key words: nano-strontiumcarbonate, SrCO₃/APcompositeparticle, impactsensitivity, thermaldecomposition, negativecatalysis