Pyrolysis behaviors of polyethylene terephthalate (PET): A density functional study

In this paper, the pyrolysis mechanism of polyethylene terephthalate (PET), which accounts for a large proportion in plastics component, is investigated by density functional theory (DFT). The dissociation energies of the several important bonds in PET are calculated. The results indicate that the C–C bond between two carboxyl groups in ethylene terephthalate is very weak, followed by the single bond between carboxyl group and carbon atom. The kinetic analysis shows the energy barriers of the reactions to release CO 2 are stable while that of CO fluctuates. In addition, the reaction paths of the formation of cyclic compounds are proposed.