Environmentally Adaptive Vitrimer Adhesives: Enhancing Dismantlability and Recyclability by Introducing Polyrotaxane Networks.

Developing sustainable and multifunctional adhesives has become imperative in the context of circular materials and environmentally responsible manufacturing. Achieving a balance between high adhesion strength at ambient temperature and efficient dismantlability at an elevated temperature remains a central challenge in the design of reusable adhesives. To address this gap, this work introduces a polyrotaxane-containing epoxy vitrimer (VPR) that exhibits high adhesive strength, dismantlability, reusability, and thermal stress relaxation. The polyrotaxane, consisting of α-cyclodextrins grafted with polycaprolactone (PCL) side chains and threaded on a poly-(ethylene glycol) axis, is covalently incorporated into the vitrimer network via transesterification. The VPR demonstrates excellent adhesive toughness at 25 °C and efficient bond exchange above 180 °C, enabling readhesion and substrate recyclability. Compared with conventional epoxy networks and PCL-modified vitrimers, VPR exhibits enhanced dismantling ability and minimal thermal warpage in bonded structures. These properties can be attributed to the dynamic molecular mobility and efficient stress dissipation enabled by the polyrotaxane moiety. Overall, this work presents a versatile strategy for designing next-generation adhesives, demonstrating excellent performance, reusability, and environmental compatibility.