Thermal stability of gamma-irradiated polyurethane/POSS hybrid materials

Through temperature-programmed pyrolysis, the physicochemical properties of Pteria martensii (PM) before and after calcination are investigated. Our results show that the mass loss is 11.02% from room temperature to 600 °C with an average mass loss rate of 0.19% per min. The decomposition of organics coupling with the phase transition of calcium carbonate from aragonite to calcite occurs in the range of 367.4–423.0 °C, as confirmed by X-ray diffraction and Fourier transform infrared spectroscopy analyses. The decomposition pores and channels are changed forming complex porous structures. The surface of sample shows a much rougher fracture, with higher C, O and N element concentrations. At the stage of decomposition and phase transition of organics, the average activation energy value is 118.78 kJ mol^?1. This study provides valuable information on the calcination process and calcined PM for use in medicines.