Biobased Polyester Network from 2,5-Furandicarboxylic Acid and 5,5′-((Dodecylazanediyl)bis(methylene))bis(furan-5,2-diyl))dimethanol: Shape Memory, Adhesiveness, Self-Healing, and Recyclability

The preparation of recyclable multifunctional biobased cross-linked polymers for different application environments and reducing dependence on petroleum products are important for sustainable development. Herein, we successfully synthesized a series of environmentally friendly, shape memory, adhesion, self-healing, and recyclable biobased polyester networks using 2,5-furandicarboxylic acid (FDCA) and 5,5′-((dodecylazanediyl)bis(methylene))bis(furan-5,2-diyl))dimethanol (DoDM) derived from renewable materials by introducing reversible Diels–Alder bonds with the addition of bismaleimide (BMI). Profiting from the freely rotating difuran ring group in DoDM, the cross-linked network with tunable thermal and mechanical properties can be constructed and present fascinating versatility. A kinetic analysis suggests that the reaction follows second-order kinetics, and the calculated activation energy is 48.1 kJ/mol with an optimal temperature of 60 °C. Different cross-linking densities of PDoF/BMI networks result in glass transition temperatures varying from 19 to 47 °C, tensile moduli from 22 to 529 MPa, and elongations at break from 5 to 120%. The PDoF/BMI network has a good shape memory performance: it can be fixed to a temporary shape below Tg and restored to its original shape by heating above Tg, with a shape recovery rate of up to 98%. In addition, the PDoF/BMI 10:1 polymer network can be used as a solvent-free adhesive with strong adhesion to glass (3.1 ± 0.5 kPa). The dynamic bond provides a self-healing response that can repair the surface scratch damage and contribute to 87% of the tensile stress recovery. Meanwhile, the PDoF/BMI film can be recovered after shredding, implying the good recyclability of the PDoF/BMI polymer. Therefore, the PDoF/BMI polymer, as a biobased multifunctional environmentally friendly material, has potential application prospects in a wide range of practical fields.