Toughened Thermoset Blend of Epoxy With Glycidyl Terminated Polyurethane Exhibits Simultaneous Self‐Healing and Shape Memory Properties

ABSTRACT Integrating multiple functionalities and stimuli‐responsiveness in a polymer matrix is highly desirable but remains challenging. In this study, we report glycidyl‐terminated polyurethane (GPU)‐induced tunability of glass transition temperature ( T g ), mechanical toughening, self‐healing (SH), and shape memory effects (SME) in an epoxy thermoset. GPU was synthesized via a two‐stage end‐capping process involving isocyanate functionalization of hydroxyl‐terminated polybutadiene (HTPB), followed by glycidation. GPU–epoxy blends, cross‐linked with a polyether diamine, were analyzed to investigate hydrogen bonding, phase morphology, and segmental dynamics. The networks exhibited tunable glass transition temperature, T g in the range of 40°C–80°C and enhanced fracture toughness, showing a 20% increase in K IC and a 270% increase in G IC at 15 wt.% GPU compared to the pristine epoxy matrix. Self‐healing was demonstrated by crack disappearance and 30%–40% strain recovery after 5 min at 80°C. The blends also exhibited dual‐shape memory behavior, with 99% shape fixity and increasing shape recovery (70%–88%) with increasing GPU content. At 20 wt.% GPU, a triple‐shape memory effect was observed, with both fixity and recovery values exceeding 90%. This study highlights a facile blending approach for developing smart epoxy resins without relying on time‐ and cost‐intensive dynamic covalent bond chemistries.