Engineering Strategies for Circular Polymer Systems: A Review of Recycling Technologies and Process Innovations

ABSTRACT Modern industries rely heavily on polymeric materials for their performance advantages, yet rising sustainability goals highlight the increasing unsustainability of linear, disposal‐based production models due to persistent waste streams and environmental impacts. Therefore, design for recyclability (DfR) has emerged as a key strategy for circular polymer systems by embedding end‐of‐life considerations at the earliest stages of product design. Recycling efficiency and economic viability are strongly influenced by design parameters such as monomer architecture, additive selection, product configuration, and compatibility with existing recycling infrastructure. This review specifically focuses on mechanical recycling and depolymerization‐based chemical recycling, where material design plays a critical role in determining recyclability and value retention. While other circular strategies such as biodegradation and energy recovery are important, they are beyond the primary scope of this review. Recent advances in polymer science including depolymerizable polymers, dynamic covalent bonds, and reversible crosslinked systems enable improved recyclability without sacrificing performance. Complementary process and system level approaches, including closed‐loop recycling, industrial symbiosis, digital material tracking, and certification schemes, are essential for successful industrial implementation. This review surveys DfR strategies spanning material and process scales and discusses their potential to enable scalable circular polymer systems.