Scalable Upcycling of Mixed Plastics into High-Performance Covalent Adaptable Networks

The effective upcycling of mixed plastic waste is hindered by polymer immiscibility and the lack of scalable compatibilization strategies. Herein, we report a solvent-free, one-pot reactive extrusion process that transforms heterogeneous plastic blends─including postconsumer waste─into high-performance covalent adaptable networks using commercially available biosourced additives (itaconic anhydride and d-sorbitol). This integrated approach simultaneously induces chain scission, radical grafting, and dynamic cross-linking, achieving intrinsic catalysis and exceptional interfacial adhesion without presynthesized compatibilizers. The resulting materials exhibit a 221% increase in tensile strength (from 8 to 25.8 MPa) and 10-fold enhancement in fracture toughness for PP/PET blends, while retaining >90% of their mechanical properties after three reprocessing cycles. The strategy is universal across diverse systems (PP/PET, PE/PET, PP/PC, PE/ABS/PET), demonstrating broad applicability. Artificial intelligence-assisted life cycle assessment reveals significant reductions in greenhouse gas emissions compared to conventional recycling or virgin production. This work presents a scalable, green, and economically viable pathway for transforming plastic waste into circular, high-value materials, bridging laboratory innovation with industrial implementation.