Recyclable biobased materials based on Diels-Alder cycloaddition

Poly(ethylene glycol) diglycidyl ether-furfurylamine (PGFA) containing pendant furan was synthesized, and a series of crosslinked materials with thermally reversible capacity were synthesized through a furan/maleimide Diels-Alder (DA) reaction between PGFA and bismaleimide (BMI). The kinetics of the PGFA/BMI DA reaction were studied by Fourier transform infrared spectroscopy (FTIR). The reaction conversion rate, the reaction rate constant, and the energy of the DA reaction at different temperatures were calculated. In addition, the retro Diels-Alder (rDA) reaction was studied via H-1-NMR, differential scanning calorimetry, and in situ FTIR. The occurrence of the retro DA reaction has been characterized clearly. Finally, the mechanical properties of the materials were obtained by dynamic mechanical and tensile tests. The storage modulus decreased obviously when the temperature reached over 90 degrees C, which proved that the materials were thermally reversible at high temperature. By changing the proportion of the crosslinking agent BMI, the best-performing materials were obtained, and the properties of the materials were basically unchanged after recycling. Thus we have obtained an excellent reusable material. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47352.