Polybutadiene derived allophanate as the crosslinker for Diels–Alder type self-healing polyurethane networks

Intrinsic self-healing materials have drawn great interest in recent years. The design of novel building blocks is essential for developing polymer networks with different properties. Allophanate is usually regarded as a side product during the preparation of polyurethanes. During the research of self-healing polyurethane networks, we have studied the terminal functionalization of hydroxyl-terminated polybutadiene with furfuryl isocyanate and occasionally obtained the furan-terminated polybutadiene allophanate. The tetra-branched molecule is employed as the crosslinker in the construction of a series of Diels–Alder type polyurethane networks. These polyurethane networks exhibit good mechanical performance and excellent self-healing ability. Damages can be healed via the thermo-promoted dissociation and recombination cycle, giving good to excellent recovery of tensile strength within three cycles of “damage-repair” processes.