Affiliation:
1. National Special Superfine Powder Engineering Research Center of China School of Chemistry and Chemical Engineering Nanjing University of Science and Technology Nanjing 210094 China
2. Jiangxi Aerospace Jingwei Chemical Co., Ltd Ji' an 343000 China
3. Key Laboratory of Soft Chemistry and Functional Materials of Education Ministry School of Chemistry and Chemical Engineering Nanjing University of Science and Technology Nanjing 210094 China
Abstract
AbstractTo improve the ignition and combustion performance of boron (B), the B@ potassium perchlorate (KP) composite micro‐units are successfully prepared by recrystallization of solvent evaporation. The morphology and structural composition show that B@KP composite micro‐units are formed by the gentle recrystallization of KP at the heterogeneous interface between B particles and solvents. It is shown by thermal analysis that the initial thermal decomposition temperature of KP is reduced by 49 °C due to the reduction of particle size. In addition, the heat of 420 J/g released by the thermal decomposition of KP is beneficial to the evaporation of the oxide boron (B2O3) film on the surface of B, which reduces the initial oxidation temperature of B by 185 °C and improves the ignition performance of B. Interestingly, the oxygen (O2) released by the thermal decomposition of KP quickly reacts with B to release heat of 3608 J/g, which improves the combustion performance of B. The optimal mass ratio of B to KP is 1: 5, which results in the ignition delay time of 641 ms, a reduction of 19 ms compared to the physical mixed sample. The ignition delay times of other samples are 724 ms, 680 ms and 650 ms respectively, and B could not be ignited successfully. In the combustion process, all samples emit a bright green flame of B combustion, and even a fierce combustion flame like a mushroom cloud appears. In a word, the B@KP composite micro‐units have great potential for application in solid propellants.