Preparation and Combustion Performance of B/PVDF/Al Composite Microspheres

In order to solve the problems that boron nanoparticles (B NPs) are easy to agglomerate, low in combustion efficiency and difficult to ignite, 80 nm B NPs were doped with 50 nm aluminum nanoparticles (Al NPs) by electrospraying using 10 wt % PVDF as binders. The prepared B/PVDF/Al composite microspheres with diameter of 1∼5 μm were examined by scanning electron microscopy (SEM). Elemental maps confirmed the uniform distribution of B and Al NPs with the coating of polyvinylidene fluoride (PVDF). The thermal properties were tested by thermogravimetry‐differential scanning calorimetry (TG‐DSC), and the combustion process of samples in air was recorded by a high‐speed camera. The results showed that PVDF can reacted with the oxide layer on the surface of Al (Al2O3) and B (B2O3) NPs to promote the combustion and energy release of B/PVDF/Al. In addition, the thermal reactivity of B/PVDF/Al increased as the Al NPs content increases. Al NPs could reduce the ignition energy of B/PVDF/Al, allowing it to burn stably in air. A thermal reaction mechanism was proposed to explain qualitatively the four‐stage pattern of B/PVDF/Al decomposition observed in TG‐DSC curves.