High-Performance Reversible Furan–Maleimide Resins Based on Furfuryl Glycidyl Ether and Bismaleimides.

Two reversible furan–maleimide resins, in which there are rigid -Ph-CH₂-Ph- structures and flexible -(CH₂)₆- structures in bismaleimides, were synthesized from furfuryl glycidyl ethers (FGE), 4,4′-diaminodiphenyl ether (ODA), N,N'-4,4′-diphenylmethane-bismaleimide (DBMI), and N,N′-hexamethylene-bismaleimide (HBMI). The structures of the resins were confirmed using Fourier transform infrared analysis, and the thermoreversibility was evidenced using differential scanning calorimetry (DSC) analysis, as well as the sol-gel transformation process. Mechanical properties and recyclability of the resins were preliminarily evaluated using the flexural test. The results show the Diels–Alder (DA) reaction occurs at about 90 °C and the reversible DA reaction occurs at 130–140 °C for the furan–maleimide resin. Thermally reversible furan–maleimide resins have high mechanical properties. The flexural strength of cured FGE-ODA-HBMI resin arrives at 141 MPa. The resins have a repair efficiency of over 75%. After being hot-pressed three times, two resins display flexural strength higher than 80 MPa. [ABSTRACT FROM AUTHOR]