Methods of chemical deconstruction and upcycling of polyethylene terephthalate using carbonate compounds

A method of deconstructing and upcycling polyethylene terephthalate (PET) waste into at least one useful breakdown product, the method comprising contacting the PET waste (1) with a catalyst that facilitates a transesterification reaction in the presence of an R-functionalized carbonate molecule (2) under transesterification conditions to produce a terephthalate monomer (3), according to the following reaction scheme:

• wherein:
• R is a hydrocarbon group containing 1-30 carbon atoms and optionally containing one or more heteroatoms selected from N, O, S, P, B, Si, and halogen atoms, wherein the two R groups in molecule (2) may be the same or different and the two R groups in molecule (3) may be the same or different;
• n is at least 10;
• and
• the symbol Δ denotes an elevated temperature sufficient to promote a transesterification reaction between (1) and (2) in the presence of the catalyst;
• provided that the R-functionalized carbonate molecule (2) functions as both a reactant and a solvent in the reaction, and no co-solvent is present in the reaction.