Vinylogous Urethane Vitrimers Derived from Styrene Copolymers for Reprocessable Damping Materials

As a novel class of materials that combine the robustness of thermosets and the recyclability of thermoplastics, vitrimers have attracted intensive attentions. Most vitrimers currently rely on specially designed polymers containing exchangeable bonds, which are commonly expensive and require a tedious preparation procedure. Therefore, a facile and commercially feasible approach for the construction of vitrimer remains highly desirable. In this work, we report a catalyst-free vitrimer derived from a random copolymer of styrene (St) and 2-(methacryloyloxy)ethyl acetoacetate (AAEMA) (PSA), cross-linked with flexible polyetheramines. The resulting vinylogous urethane (VU) networks integrate the rigid polystyrene backbones with the flexible polyetheramine cross-linkers. By varying the AAEMA content and cross-linker type (D230 or D400), a series of PSA-based vitrimers were synthesized, exhibiting tunable Tg (ranging from 14 °C to 75 °C), adjustable damping properties (effective damping temperature range from −6 °C to 100.6 °C, tan δ > 0.3), and good mechanical performance. Notably, these vitrimers have potential as promising damping materials with a wide temperature window around ambient temperature. Furthermore, due to the dynamic nature of the VU bonds, the PSA-based vitrimers can be reprocessed with minimal property loss (over 90% of their mechanical strength was retained after two reprocessing cycles). This work presents a universal and scalable strategy to construct high-performance vitrimers based on commercial monomers and cross-linkers, offering a pathway for reprocessable damping thermosets with adjustable damping properties.