Chemically recyclable epoxy resins: from performance evaluation to application demonstration

Epoxy resins are a class of important thermosetting resins widely used in fields such as aerospace, rail transportation, and electronic appliances. However, cured epoxy resins possess a three-dimensional cross-linked network, rendering them insoluble and infusible, which makes degradation and recycling particularly challenging. After being discarded, disposal mainly involves landfilling or incineration, leading to significant environmental pollution and resource wastage, which has garnered widespread attention. Existing strategies reported to date, including high-temperature pyrolysis, treatment with strong acids/alkalis/oxidizing agents, and the synthesis of novel resins containing dynamic bonds, generally difficult to simultaneously meet the requirements for long-term service stability and mild degradation/recycling conditions. This paper primarily summarizes recent research progress by our group in the preparation of chemically recyclable epoxy resins. It systematically introduces their batch-scale preparation, hydrothermal aging behavior, and degradation/reusability performance. Furthermore, successful application demonstrations in areas such as composites and electrical insulating materials are presented.