Effect of the catalyst MCM-41 on the kinetic of the thermal decomposition of poly(ethylene terephthalate).

The aim of this work is to determine the activation energy for the thermal decomposition of poly(ethylene terephthalate)—PET, in the presence of a MCM-41 mesoporous catalyst. This material was synthesized by the hydrothermal method, using cetyltrimethylammonium as template. The PET sample has been submitted to thermal degradation alone and in presence of MCM-41 catalyst at a concentration of 25% in mass (MCM-41/PET). The degradation process was evaluated by thermogravimetry, at temperature range from 350 to 500 °C, under nitrogen atmosphere, with heating rates of 5, 10 and 25 °C min⁻¹. From TG, the activation energy, determined using the Flynn–Wall kinetic method, decreased from 231 kJ mol⁻¹, for the pure polymer (PET), to 195 kJ mol⁻¹, in the presence of the material (MCM-41/PET), showing the catalyst efficiency for the polymer decomposition process. [ABSTRACT FROM AUTHOR]