Reactive Polymer Compatibilizers for Recycling of Mixed Plastic Waste

Mixed plastics pose a challenge to mechanical recycling, which is sensitive to imprecise sorting or contamination across single-polymer streams. Development of compatibilizers that increase miscibility and decrease phase separation between polymers can improve recyclability and produce blends whose properties are comparable to virgin plastics. We aim to develop a reactive block copolymer system by tuning the reactivity of poly(glycidyl methacrylate) (PGMA) compatibilizers to optimize interactions with polyethylene terephthalate (PET) end groups. We synthesized a library of thiol-functionalized PGMA polymers to study the effect of compatibilizer structure, quantified by number of reactive groups, on crosslinking reactions. Crosslinking is initiated during extrusion of PGMA with PET. The cross-linking density is quantified with spectroscopy and the PET crystallinity is determined with WAXS. These results will be translated to a block copolymer system to compatibilize mixed waste plastic streams.