Compatibilization of Polyethylene and Polypropylene via Dynamic Cross-Linking

Despite similar hydrocarbon compositions, polyethylene (PE) and polypropylene (PP) are mutually immiscible, posing challenges to their recycling. Consequently, significant research efforts have been made on PE/PP compatibilization. In this study, we transformed physical blends of PE and PP into dynamic covalent polymer networks by taking advantage of reversible boronate ester bonds. The dynamically cross-linked network “welds” PE and PP phases together, enabling PE–PP interfacial compatibilization through morphological control and converting the otherwise brittle PE and PP blend into a tough PE/PP hybrid plastic.