Thermal decomposition kinetics of a mixture of energetic polymer and nitramine oxidizer

Energetic glycidyl azide polymer (GAP) was synthesized from polyepichlorohydrin (PECH) precursor. Thermal decomposition behavior of a mixture of GAP and nitramine oxidizer (4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazaisowurtzitane (TEX)) was investigated by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). It was found that the decomposition temperature of TEX is unaffected by the presence of GAP in the GAP/TEX mixture. Kinetics of degradation of GAP/TEX mixture was studied by a model-free method and the results were compared with that of the pure components. The study suggested that the decomposition kinetics is controlled by the degradation of GAP during the initial stages of conversion (α > 0.25) whereas the later stages (0.25 ≤ α ≤ 1) are determined by that of TEX. Mechanistic interpretation has been provided to the observed activation energy dependencies by using a combination of optical microscopy (OM) and Fourier transform infrared spectroscopy (FTIR).