Self‐Healing Epoxy Resin Incorporating Flexible Siloxane and Exchangeable Disulfide Crosslinks

ABSTRACT Traditional epoxy resins are widely used in various applications due to their excellent performance. However, their highly stable cross‐linked networks prevent autonomous repair after mechanical damage, thereby limiting their long‐term durability. Herein, a novel epoxy system (EDA‐X) was produced through copolymerization of bisphenol A epoxy resin (E51) with siloxane containing epoxy groups (DGETDS), using an amine curing agent (AFD) containing dynamic disulfide bonds. The single glass transition temperature confirmed excellent epoxy‐silicone compatibility. The effects of DGETDS and AFD content on the mechanical and self‐healing properties were systematically investigated. The results demonstrated that more flexible siloxane and dynamic disulfide bonds enhance the self‐healing efficiency while reducing mechanical strength. Notably, EDA‐7 obtained appropriate mechanical strength (59.21 ± 1.50 MPa), outstanding self‐healing efficiency (~86.18%) and good reprocessability. This work provides an efficient strategy for designing high‐performance self‐healing epoxy resins.