Enhancement on performance of molecular perovskite energetic material DAP-4 by boron element based thermites paired with bismuth oxyhalide BiOX(X=Cl,Br)

Abstract

As a new type of catalytic material, thermite is of great importance in promoting the overall performance of molecular perovskite energy materials. In this paper, the thermal decomposition and combustion effects of nano-boron/bismuth oxyhalide (nB/BiOClBr) composite microspheres on molecular perovskite energetic material (DAP-4) have been studied. In this study, 5, 10, 15, 20 and 30 %nB/BiOClBr/DAP-4 mixtures were prepared by solvent evaporation. The thermal decomposition and combustion properties of nB/BiOClBr/DAP-4 were characterised. The experimental results showed that nB/BiOClBr was capable of catalysis of thermal decomposition and combustion of DAP-4. When nB/BiOClBr was added at 15 %, which was the optimum preparation ratio, the activation energy required for the thermal decomposition reaction of nB/BiOClBr/DAP-4 was the lowest, 135.6 kj/mol, and it was able to significantly lower the peak temperature of the exothermic decomposition of DAP-4. During the combustion process, the addition of 15 %nB/BiOClBr significantly increased the combustion intensity of DAP-4, increasing the combustion pressure up to 1.5 MPa, resulting in a combustion rate of 3.59 MPa/s, releasing more combustion heat compared to the feedstock and other proportions of the nB/BiOClBr/DAP-4 blends. Based on the results of thermal analyses and combustion tests, a possible combustion mechanism for nB/BiOClBr/DAP-4 composites was proposed. This work provides a new idea to improve the combustion performance of DAP-4 using novel catalysts.