Thermal decomposition mechanism of Co-ANPyO/CNTs nanocomposites and their application to the thermal decomposition of ammonium perchlorate

A chemical precipitation method was used to prepare cobalt complexes of 2,6-diamino-3,5-dinitropyridine-1-oxide/carbon nanotube (Co-ANPyO/CNTs) nanocomposites. The structure and thermal analyses indicate that Co-ANPyO nanoparticles are well dispersed on the surface of CNTs with an average particle size of about 10 nm, the content of Co-ANPyO nanoparticles in nanocomposites is about 73.4 wt%. The thermal decomposition mechanism of Co-ANPyO and Co-ANPyO/CNTs nanocomposites were predicted based on thermogravimetry-differential scanning calorimetry (TG-DSC) and thermolysis in situ rapid-scan FTIR (RSFTIR) results. The thermal decomposition of Co-ANPyO and Co-ANPyO/CNTs nanocomposites contains two exothermic processes in the temperature range of 25-490 degrees C. The first exothermic process for Co-ANPyO/CNTs nanocomposites shifts towards lower temperatures compared to that of Co-ANPyO. The main products of the final residues for Co-ANPyO and Co-ANPyO/CNTs nanocomposites at 490 degrees C are Co3O4 and CoO, respectively. The catalytic performance of Co-ANPyO and Co-ANPyO/CNTs nanocomposites on thermal decomposition of ammonium perchlorate (AP) was investigated by TG-derivative thermogravimetry (DTG), DSC, non-isothermal kinetic and alpha-T kinetic curves analyses. The possible catalytic mechanism was also discussed and proposed. During the thermal decomposition process of AP with Co-ANPyO/CNTs nanocomposites, Co-ANPyO/CNTs nanocomposites might decompose and form Co3O4/CNTs and CoO/CNTs nanocomposites as high activity catalysts, which could accelerate the thermal decomposition of AP. Thus, Co-ANPyO/CNTs nanocomposites not only lower the decomposition temperature and activation energy, but also enhance the total heat of AP, which could not be achieved by the CNTs and Co-ANPyO alone. The way of preparing Co-ANPyO/CNTs nanocomposites presented in this work can be expanded to other energetic additives/CNTs nanocomposites used for AP and AP based propellants.