Polyethylene terephthalate (PET) is the largest produced polyester globally with an annual production exceeding 26 million tons for use in carpet, clothing, and single-use beverage bottles, among others. Today, only PET bottles are reclaimed for recycling, albeit at a low reclamation rate, with most of the waste PET accumulating in landfills or the environment. In this study, PET is upcycled to higher-value, long-lifetime materials, namely two types of fiber-reinforced plastics (FRPs), via combination with renewably sourceable monomers. By harnessing the embodied energy in reclaimed PET (rPET) and implementing renewably sourceable monomers with distinct chemical functionality relative to petroleum building blocks, the resultant rPET-FRPs exhibit considerably improved material properties and are predicted to save 57% in the total supply chain energy and reduce greenhouse gas emissions by 40% over standard petroleum-based FRPs. Overall, this study enables a route to PET upcycling via bio-based monomers that could incentivize both improved plastics reclamation and acceleration of the bioeconomy…read more