Preparation and Thermal Decomposition Characteristics of Energetic Metastable Intermodular Composite Si@PVDF/CL-20.

In order to improve the energy efficiency of composite nano-metal materials, the energetic intermolecular complexes Si@PVDF/CL-20 with different silicon content (20%, 30% and 40%)were prepared by electrostatic spray method. The heat of combustion of PVDF/CL-20 composites with different ratios was obtained by bomb calorimeter. The morphology of PVDF/CL-20 composite was clarified by using SEM. The effect of Si content on the morphology of Si@PVDF/CL-20 composite particles was also analyzed. The thermal behavior of energetic compounds with different silicon content was studied by DSC-TG, and the kinetic paramters of thermal decomposition were calculated. The thermal analyses indicate that when the PVDF/ CL-20 mass ratio is 1-6, the heat of combustion reaches a maximum value, which can be used as the optimal ratio incoating of nano-Si powder. The SEM results show that when the silicon content is 30%, the composite particles (Si-30% ©PVDF/CL-20) exhibite the best sphericity. The DSC results show that when the silicon content is 20%, a runaway chemical reaction was likely occurred. The effect of Si powder on the decomposition of PVDF/CL-20 composite plays less significant role with the increase of content. The apparent activation energies of Si@PVDF/CL-20 composites calculated by Friedman method are 470. 6, 182.1, 91.7kJ/mol, respectively. The complex decomposition process of Si-20% @PVDF/CL-20 cannot be described by a single kinetic model, whereas those of Si-30% ©PVDF/CL-20 and Si-40% ©PVDF/CL-20 can be well described by a nuclea-tion and growth model. [ABSTRACT FROM AUTHOR]