the effect of zsm-5 zeolite acidity on the catalytic degradation of high-density polyethylene using simultaneous dsc/tg analysis

the simultaneous use of the signals from the tg and dsc allowed the development of a kinetic model that is able to accurately describe all the runs performed, both the thermal and the catalytic degradation of the polymer. the kinetic parameters obtained clearly revealed the reduction in the activation energy due to the presence of the catalyst and its relation to the overall acidity of the samples. the gases evolved from the pyrolysis of polyethylene were also analysed using gas chromatography, and it was also found that volatile product selectivity changes with the catalyst acidity.

the fact that the overall activity for the catalytic cracking of hdpe on these zeolites varies with internal acid strength of the zeolite indicates that the inner surface of these zeolites participates in this reaction despite the fact that the reactant molecules are extremely large.