Design of Copolymer‐Based Blend Compatibilizers for Mixed Plastic Recycling

Abstract Mixed plastic waste recycling represents a significant challenge as the phase separation of different components dictates downgraded performance. Polymer‐based compatibilizers can offer a promising solution to address this issue, through effectively reducing surface tension and increasing interfacial strength between distinct components to result in improved mechanical and thermal properties of recycled products. This perspective provides an overview of the fundamental concepts for the rational design of copolymer blend compatibilizers and discusses their recent advances, including both preformed and in situ generated systems. Impacts of key material parameters of compatibilizers, such as chain topology, chemical composition, and block sequence on their performance of remediating mixed plastics are discussed. Additionally, reactive compatibilization strategies are also introduced, including in situ formation of polymers, installing functional groups on mixed plastics, and employing dual compatibilization strategies. Looking forward, there are many research and technology opportunities in this area, especially for enabling the use of blend compatibilizers to practically address mixed plastic wastes at scale. Specifically, future compatibilizer design and application should provide strong competitiveness in both cost and energy savings, and carbon emission reduction. Together, the development of blend compatibilizers is an important step in establishing plastic circular economy and creating a more sustainable future.