The inexpensive manufacturing, long-term durability, and high resistance to degradation of plastics has led to its concerning accumulation as waste in landfills and oceans at rates that parallel its annual production. The primary sources of plastic waste are single-use or shortlifetime consumer plastics, mainly polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP), with PET being the predominant polymer in post-consumer domestic plastic waste collected in countries such as the UK (40% abundance). Although PET is recognized as one of the most recyclable plastics due to the vast presence of mechanical recycling industries, it can only endure a limited number of cycles before its properties are compromised. For example, the tensile and impact strength of virgin PET used in bottles decreases almost linearly within the first 3 extrusion cycles, whereas its ductility is reduced from >200% to <10% elongation at break upon mechanical recycling. Consequently, recycled PET ends up being used in lower-grade PET applications that are seldom recycled, breaking the circularity of this process.