超级铝热剂Al/Fe_2O_3对硝化棉热分解特性的影响

采用水热法制备了纳米Fe_2O_3,并用超声分散法将其与纳米Al颗粒复合制备了超级铝热剂Al/Fe_2O_3,利用X-射线粉末衍射(XRD)、透射电子显微镜(TEM)、扫描电镜及能量散射光谱仪(SEM-EDS)对复合物的物相、组成、形貌和结构进行了分析表征,采用差示扫描量热法(DSC)和热红联用技术(TG-FTIR)研究了Al/Fe_2O_3对硝化棉(NC)热分解过程的影响。结果表明,Al/Fe_2O_3-NC和NC的热分解过程遵循Avrami-Erofeev方程f(α)=1.5(1-α)-ln(1-α)]1/3;超级铝热剂Al/Fe_2O_3可降低硝化棉的表观活化能、临界点火温度和临界爆炸温度,在促进硝化棉O-NO_2键断裂和凝聚相二次自催化反应中起到至关重要的作用。

Effects of Superthermite Al/Fe2O3 on the Thermal Decomposition Characteristics of Nitrocellulose

The nano-Fe2O3 was prepared by hydrothermal method, and then combined with Al nanoparticles using ultrasonic dispersion method to prepare superthermite Al/Fe2O3. The physical phase, composition, morphology and structure of the composite were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscope-energy dispersive spectrometer (SEM-EDS). The differential scanning calorimetry (DSC) and the thermogravimetry with Fourier transform infrared analysis (TG-FTIR) were employed to investigate the effects of the superthermite Al/Fe2O3 on the thermal decomposition process of nitrocellulose (NC). The results show that the thermal decomposition reactions of Al/Fe2O3-NC composite and NC follow the same thermal decomposition mechanism with the Avrami-Erofeev equation of f(α)=1.5(1-α)-ln(1-α)]1/3. The superthermite Al/Fe2O3 can reduce the activation energy of the decomposition reaction, the thermal ignition temperature and the critical temperature of thermal explosion of NC,and it plays a crucial role in promoting the O-NO2 bond cleavage of NC and secondary autocatalytic reactions in condensed phase.