Novel polyurethane with high self-healing efficiency for functional energetic composites

Self-healing polymeric materials have attracted considerable interests due to the capability of healing the cracks generated in functional materials autonomously, resulting in improved reliability and life cycle. This paper is intended to develop a self-healing polymeric binder for energetic composites by incorporation of reversible covalent bonds into polyurethane. A novel polyurethane was synthesized from NCO-terminated prepolymer with furfuryl amine, and cross-linked with bismaleimide via Diels-Alder (DA) reaction. The chemical structures of the intermediates and products of Diels-Alder polyurethane (DAPU) were firstly confirmed by nuclear magnetic resonance (H-1 NMR), Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Then, the thermal reversibility and the self-healing performances of DAPU based energetic composites were systematically studied by DSC, polarizing optical microscopy (POM) and tensile testing. All the results showed that the as-prepared DAPU had high self-healing efficiency and remarkable mechanical performance, providing potential applications as a promising self-healing material in repairing the cracks generated in energetic composites.