Dynamic ester bond cross-linking network based on isomannitol

This paper presents the development of recyclable and repairable dynamic ester cross-linked network bio-based Vitrimer (IMT-PER-COO). Pentaerythritol (PER) is used as the crosslinking agent in IMT-PER-COO to form a topological network through hydroxyl groups in PER and isocyanate groups in 1,6-hexamethylene diisocyanate (HDI). At 150 ℃, the carbamate bond is simultaneously broken and associated, and the topological network is remapped to achieve the goal of material self-repair. The results showed that the successful synthesis of IMT-PER-COO was confirmed by FTIR, XRD and XPS. The DMA test confirmed the movement of the polymer chain segment at high temperature. In addition, with the increase of PER content, the glass transition temperature (Tg) of the material increased, and the thermal stability and mechanical properties were improved. The repairability of the IMT-PER-COO material has also been confirmed. This technology introduces bio-based IMT into the covalent adaptive network, which has great potential for the further development of environmentally friendly materials.