Kinetic study of thermocatalytic degradation of UHMWPE over microporous and hierarchical ZSM-23 zeolite

The catalytic degradation of ultra high molecular weight polyethylene was studied in the presence of micro- porous and hierarchical ZSM-23 zeolites by thermogravimetric analysis. The ZSM-23 was synthesized using different structure-directing agents and subsequently subjected to post-synthesis treatment. The materials characterization were carried out by dispersive energy X-ray spectrometry, X-ray diffraction, temperature programmed desorption of ammonia and nitrogen adsorption-desorption measurements. The obtained zeolites were physically mixed with polymer in the proportion of 30 %wt and submitted to thermogravimetric analyses at heating rates of 5, 10, 20 and 30 degrees C.min(-1). The average activation energy for the process was determined from the model-free kinetic proposed by Flynn-Wall-Ozawa. The modified zeolites presented a secondary porosity, which reflected in high values of external surface area and acidity, and demonstrated higher conversion efficiency and lower energy level required in polymer degradation compared to the parent samples.