Recyclable, self-healing itaconic acid-based polyurethane networks with dynamic boronic ester bonds for recoverable adhesion application

Currently, synthesis of biobased polyurethane (PU) networks with recyclability, self-healing, as well as robust mechanical and adhesion properties still remain a challenge. Herein, a series of robust itaconic acid-based polyurethane networks (IAPU) with dynamic boronic ester bonds are fabricated and fully characterized by FTIR and DMA . All the obtained IAPU networks display high thermostability with an initial decomposition temperature around ∼270 °C. The activation energy and typology transition temperature of the IAPU-80 are 71.9 kJ mol −1 and -25.8 °C, respectively. The IAPU-80 shows low relaxation times from 169 to 125 s at moderate temperature from 60 to 65 °C, respectively, as well as excellent mechanical properties (tensile strength = 15.6 MPa, elongation at break = 70.4%, toughness = 12.6 MJ m −3 ). The IAPU-80 possess outstanding scratch self-healing ability (scratch disappear after heating at 120 °C for 10 min) and reprocessability (without distinct decrement of the tensile strength after twice recycling). Remarkably, the IAPU-80 bonded wood sample exhibits a high recoverable adhesion strength (∼8.2 MPa), after reused for three times. Therefore, the self-healing and malleable IAPUs with recoverable adhesion performance are obtained by incorporating dynamic boronic ester bonds into itaconic acid-based polyurethane networks. Present work describes a green and facile way to prepare sustainable PU networks with multiple functionalities for wide applications.