铝粉粒度对高氯酸铵热分解动力学的影响

采用热重-差示扫描量热(TG-DSC)联合技术研究了10.7 μm, 2.6 μm和40 nm铝粉对高氯酸铵(AP)热分解的影响. 结果表明, 铝粉的加入对AP的低温放热峰有抑制作用, 对高温放热分解反应有促进作用, 并且随铝含量的增加和铝粒径的减小这种作用更强烈. 采用多元非线性拟合技术对不同升温速率下TG-DSC实验数据进行拟合, 结果表明, 质量分数为40%的不同粒径铝粉的加入对AP的热分解三阶段(A→B→C→D)反应模型无影响, 但反应机理函数发生了改变. 纯AP, AP/Al(10.7 μm), AP/Al(2.6 μm)及AP/Al(40 nm)的反应机理函数组合分别为C1/D1/D1, C1/D1/D3, C1/D1/D4和C1/D1/F2.

Effect of Aluminum Particle Size on Thermal Decomposition of AP

The effect of aluminum particle sizes of 10.7 μm, 2.6 μm and 40 nm on the thermal decomposition of ammonium perchlorate(AP) was investigated by thermogravimetry-Differential Scanning Calorimetry(TG-DSC). The addition of Al resulted in an increase in the temperature of the low-temperature exothermic peak and a decrease in the temperature of the high-temperature exothermic peak of AP. These changes were more pronounced with an increase in the Al content and a decrease in the aluminum particle size. The processing of non-isothermal data at various heating rates without and with 40%(mass fraction) Al was performed by Netzsch thermokinetics. The dependence of the activation energy calculated by Friedman's isoconversional method on the conversion degree indicated the decomposition process can be divided into three steps for AP and all the AP/Al mixtures determined by multivariate non-linear regression. They are C1/D1/D1(C1: 1st order autocatalysis; D1: one-dimension diffusion reaction) for neat AP, and change to C1/D1/D3(D3: three-dimension Jander diffusion reaction), C1/D1/D4(D4: three-dimension Ginst-Broun diffusion reaction) and C1/D1/F2(F2: 2nd order reaction) after addition of 10.7 μm, 2.6 μm and 40 nm into AP, respectively.