Functional materials derived from chemical depolymerization-conversion of polyethylene terephthalate

Polyethylene terephthalate (PET) finds extensive applications in the textile and packaging industries. However, the mechanical recycling of PET is constrained by value degradation, leading to a bottleneck in the recycling rate. Chemical recycling of PET consists of two processes: depolymerization and conversion into value-added materials. Compared to mechanical recycling, chemical recycling faces more complex procedures and higher costs, hindering its large-scale industrial application. Enhancing the added value of the converted derivative substances is critical to achieving economic viability in chemical recycling. This review summarizes recent advances in PET “efficient depolymerization” and “high-value conversion”, highlighting various chemical depolymerization methods such as pyrolysis, hydrolysis, ammonolysis, aminolysis, alcoholysis, and glycolysis, as well as the design of routes to further convert depolymerization products into functionalized polyesters, polyurethanes, and aerogel materials. This emerging direction offers promising potential in the field of PET chemical recycling.