Polyether-maleimide-based crosslinked self- healing polyurethane with Diels-Alder bonds

The Diels-Alder (DA) reaction is particularly desirable for the preparation of heat-stimuli self-healing polymeric materials because of its thermal reversibility, high yield, and minimal side reactions. Some attempts were conducted to synthesize polyether-maleimide-based crosslinked self-healing polyurethane with DA bonds (C-PEMIPU-DA) through the reactions of the prepolymer (polymeric MDI/PBA-1000) functionalized by furfuryl amine and polyether-maleimide without benzene in this study. The structures of intermediates and C-PEMIPU-DA were first confirmed by H-1-NMR, Fourier transform infrared spectroscopy, and differential scanning calorimetry. Next, the thermal reversibility and the self-healing performance of C-PEMIPU-DA were studied by H-1-NMR, polarizing optical microscopy, tensile testing, and a sol-gel process. The results show that C-PEMIPU-DA exhibited interesting properties of thermal reversibility and self-healing. The polymers could be applied to self-healing materials or recyclable materials in the fields of the repair of composite structures and aging parts because of their thermosetting properties at room temperature and thermoplasticity at higher temperatures. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41944.