Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (04): 781-786.doi: 10.3866/PKU.WHXB201202151

• THERMODYNAMICS, KINETICS, AND STRUCTURAL CHEMISTRY • Previous Articles     Next Articles

Thermal Behavior and Non-Isothermal Decomposition Reaction Kinetics of Aluminum Nanopowders Coated with an Oleic Acid/Hexogen Composite System

YAO Er-Gang, ZHAO Feng-Qi, GAO Hong-Xu, XU Si-Yu, HU Rong-Zu, HAO Hai-Xia, AN Ting, PEI Qing, XIAO Li-Bai   

  1. Science and Technology on Combustion and Explosion Laboratory, Xi'an Modern Chemistry Research Institute, Xi'an 710065, P. R. China
  • Received:2011-11-22 Revised:2012-01-16 Published:2012-03-21
  • Contact: ZHAO Feng-Qi E-mail:npecc@163.com
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21173163) and Science and Technology Foundation of Combustion and Explosion Laboratory, China (9140C3503141006).

Abstract: Aluminum nanopowders (nmAl) coated with oleic acid (OA) were obtained under nitrogen atmosphere, and their surface morphologies and structures were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. The thermal decomposition reaction kinetics of composite systems, nmAl/hexogen (RDX) and (nmAl + OA)/RDX, were investigated using differential scanning calorimetry (DSC). Their kinetic parameters and kinetic equations were obtained. The results showed that most of the OA adsorbed on the aluminum nanopowder surface by physical adsorption. Only a small amount of OA reacted with the surface aluminum atoms and adhered to the surface via chemical bonds. Compared with the nmAl/RDX composite, the peak temperatures for the (nmAl+OA)/RDX composite at multiple heating rates were lower. The apparent activation energy (Ea) and pre-exponential factor (A) of the main decomposition reaction were 141.18 kJ·mol-1 and 1012.57 s-1. The reaction mechanism fits a three-dimensional diffusion mechanism and obeys the Jander equation with n= 1/2. The kinetic equation can be expressed as: dα/dt=1013.35(1-α)2/3[1-(1-α)1/3]1/2e-16981.0/T.

Key words: Physical chemistry, Aluminum nanopowder, Oleic acid, Coating, Hexogen, Nonisothermal decomposition reaction kinetics

MSC2000: 

  • O643