Characterization of Aluminum/Poly(Vinylidene Fluoride) by Thermogravimetric Analysis, Differential Scanning Calorimetry, and Mass Spectrometry

Abstract

Fluoropolymers have been widely used as oxidizers. In this study, poly(vinylidene fluoride) was employed to oxidize nanoaluminum, and the thermal behavior was investigated by thermogravimetry combined with differential scanning calorimetry and mass spectrometry. The results show that the addition of nanoaluminum significantly decreased the thermal stability of poly(vinylidene fluoride) and that the decomposition of nanoaluminum/poly(vinylidene fluoride) occurred in two temperature ranges. The first from 200 to 280 degree Celsius involved the decomposition of adsorbed water on the nanoaluminum and the reaction of the alumina shell on the surface and dissociative fluoride. The second from 350 to 450 degrees Celsius involved the degradation of poly(vinylidene fluoride) and reaction of nanoaluminum and gas products from the polymer and its matrix. The kinetic process was divided into four steps with apparent activation energies calculated by Kissinger method of 137, 182, 163, and 176 kilojoules per mole, respectively. From evolved gas product analysis, the fluorinated products were identified from the decomposition of poly(vinylidene fluoride) and nanoaluminum/ poly(vinylidene fluoride) composites. However, the intensities of fragments from nanoaluminum/poly(vinylidene fluoride) were lower than those from pure poly(vinylidene fluoride). Other decomposition products included H2, H2O, and OH.