Acidolysis of Poly(ethylene terephthalate) Waste Using Succinic Acid under Microwave Irradiation as a New Chemical Upcycling Method

A novel method of chemical upcycling of used poly(ethylene terephthalate) (PET) bottles by acidolysis with succinic acid (SA) was performed under microwave irradiation. The long polyester chain of PET was efficiently fragmented into small molecules and oligomers, such as terephthalic acid and α,ω-dicarboxylic acid oligo(ethylene succinate-co-terephthalate) (OEST). Various input molar ratios of SA/PET from 1.0 to 2.5 were used, and the product mixtures were separated successfully. The recovered terephthalic acid can be reused as a basic chemical. The α,ω-dicarboxylic acid OEST was used as a curing agent for epoxy resin. The recovered SA can be reused for further PET acidolysis. Structures of OEST were identified by Fourier transform infrared (FTIR) spectroscopy