Kinetic parameters of polyethylene degradation by the natural zeolite chabazite

High-density polyethylene (PE) was subjected to thermal degradation alone a nd in the presence of an ammonium-exchanged zeolite chabazite (CHA/PE). The processes were carried out in a reactor connected online to a gas chromato graph/mass spectrometer in order to analyse the evolved products. Polymer d egradation was also evaluated by thermogravimetry, from room temperature up to 800 degrees C, under a dynamic nitrogen atmosphere, with multiple heati ng rates. From the TG curves, the activation energy relating to the degrada tion process was calculated by using the Flynn and Wall multiple heating ra te kinetic model for pure PE and for CHA/PE. The exchanged chabazite exhibi ted good selectivity for the catalytic degradation of PE to low molecular m ass hydrocarbons.