Theoretical study of the transesterification reaction of polyethylene terephthalate under basic conditions

Plastic Degradation and Its Environmental Implications with Special Reference to Poly(ethylene terephthalate)

“…This suggests that the reason for the extreme stability arises from being in a polymeric state. There have been a few studies that have established a link between plastic degradability and the degree of crystallisation of the polymer [39,72,73,[75][76][77]. Increased crystallisation limits chain movement and decreases the availability of polymer chains for degradative agents, such as microbial lipases or other ester lysing molecules (Figure 3).…”

Generalized kinetic analysis of heterogeneous PET glycolysis: Nucleation-controlled depolymerization

“…This macromolecular perspective on depolymerization is coherent with molecular simulation of the glycol attack on the PET chain. Simulation results revealed that glycolysis occurs through a pentagonal ring transition state, forcing the PET structure to be kinked in order to allow such configuration [36]. Due to energy barriers, chains held in place in the crystalline domains are unlikely to accommodate the bent configuration and undergo glycolysis.…”

“…For experimental work on PET model compounds and molecular simulation of PET ester bond degradation (thermal and glycolytic), activation energies of around 12e19 kJ/mol [36,38,39] were reported. Lower activation energy was obtained with low MW model compounds (single ester bond) and a somewhat higher for that of a PET model chain with periodic structure.…”

Effect of polymerization and preheating processes on poly(ethylene terephthalate) depolymerization

“…The molecular structures of the ground state (PET, alkoxide, and TPA ester) and the transition state of the depolymerization reaction were simulated. In addition, the activation energy of the depolymerization reaction was calculated from structures optimized in a minimum‐energy configuration from appropriate initial coordination of the atoms 8, 9. HF/6‐31G(d) was used as basis set and method of this calculation.…”