不同粒径黑火药点火过程中与纤维素壳体材料的热相互作用

In order to study the effect of cellulose shell on the thermal behaviors, including pyrolysis gaseous products, ignition and combustion characteristics of black powder with different particle sizes, a series of black powder/ cellulose composite samples are prepared. Various characterization techniques, including scanning electron microscopy(SEM), simultaneous thermal analysis (DSC-TG-FTIR), X-ray diffraction (XRD), bomb calorimetry, and home-made combustion diagnostic system, are used to investigate the prepared composites and their combustion condensed products (CCPs) . The results show that the overall heat releases of two black powders are decreased by 66郾 4% and 58郾 5% with the cellulose content of 33郾 3%, respectively. Moreover, the gas phase product analysis shows that the cellulose does not change the pyrolysis pathways of black powder, of which gas-phase products mainly include H₂ O, CO₂ and NO₂ . The cellulose only affects the energy release process of black powder, but has little effect on the energy release of black powder with different particle sizes, the difference between the energy release changes of these two composites is only 3郾 1% . It is found that the black powder with smaller particle size and its cellulose composite burns more violently, with larger flame area and higher combustion temperature. However, the cellulose has a negative effect on the combustion performance of black powder, mainly reducing the burning rate and flame radiation intensity of black powder, and decreasing the flame temperature by 273郾 7 益 and 299郾 4 益 . In addition, the cellulose promotes the agglomeration of condensed phase products of black powder and reduces its combustion efficiency.