Improving the Energetic and Safety Performances of Aluminum Diboride by Fabricating Microcapsule with Fluoropolymer

In current work, aluminum diboride (AlB2) is coated by polyvinylidene difluoride (PVDF) to fabricate microcapsule structure by a facile rotary evaporation method. As morphology investigation shows, PVDF has formed an intact and individual outer shell on the surface of AlB2 core. Comparing with raw AlB2, AlB2@PVDF microcapsule has shorter ignition delay time, more intense combustion with higher pressurization rate. And with appropriate PVDF ratio, the experimental combustion heat is higher than that of raw AlB2 due to sufficient combustion with a heat release efficiency of 92.3%, while the heat release efficiency of raw AlB2 is 85.2%. The mechanism investigation indicates that the decomposition product of PVDF could enhance the oxidation of AlB2 in multiple reaction stages, providing higher reactivity for AlB2@PVDF. The application of AlB2@PVDF in PBX shows that the density, detonation velocity and heat are all improved with good compatibility, and the mechanical sensitivities are also controlled at an acceptable level. It suggests that AlB2@PVDF microcapsule could be a promising metal fuel for composite energetic materials.