Super‐Tough, Self‐Healing Polyurethane Based on Diels‐Alder Bonds and Dynamic Zinc–Ligand Interactions

Abstract

Self‐healing polymer materials have attracted extensive attention and have been explored due to their ability of crack repairing in materials. This paper aims to develop a novel polyurethane‐based material with high self‐healing efficiency and excellent mechanical properties under 80 °C on the basis of reversible Diels–Alder bonds as well as zinc–ligand structure (DA‐ZN‐PU). By integrating DA bonds and zinc–ligand structure, as‐prepared DA‐ZN‐PU samples reach the maximum tensile strength as much as 28.45 MPa. After self‐healing, the tensile strength is 25.85 MPa, leading to the high self‐healing efficiency of 90.8%. In addition, by introducing carbonyl iron powder (CIP), a new polyurethane containing carbonyl iron powder (DA‐ZN‐CIP‐PU) can be achieved, exhibiting microwave‐assisted self‐healing property. And the self‐healing efficiency can be reached to 92.6% in 3 min. Due to high self‐healing efficiency and excellent mechanical properties of the prepared novel polyurethane, it has application attributes in crack repair of functional composite materials.

A Biologically Muscle‐Inspired Polyurethane with Super‐Tough, Thermal Reparable and Self‐Healing Capabilities for Stretchable Electronics

“…a) Stress–strain curves of the notched DA‐PU self‐healing at 60 °C for different periods; b) cyclic tensile test of self‐healed DA‐PU at 100% strain for 1000 times; c) macroscopic demonstration of self‐healing and toughness: DA‐PU (≈1 mm thickness) was cut into two pieces, followed by the self‐healing at 60 °C and subjecting to a 5 kg dumbbell lifting test (DA‐PU/dumbbell = 1/5000, wt/wt); d) comparison of the stretching strain, toughness, and self‐healing temperature of DA‐PU with other reported self‐healing polymers in recent 3 years. (1, [ 22 ] 2, [ 23 ] 3, [ 24 ] 4, [ 25 ] 5, [ 26 ] 6, [ 8d ] 7, [ 27 ] 8, [ 28 ] 9, [ 29 ] 10, [ 30 ] 11, [ 31 ] 12, [ 9 ] 13, [ 32 ] 14, [ 33 ] 15, [ 34 ] 16 [ 35 ] ).…”

Acceleration Effect of Dynamic Covalent Chains in a Hard Epoxy Resin on Its Thermally Induced Deformation and Healing Behavior

“…[10] For this reason, the activation energies of these reactions have to be controlled in a proper range. Possible dynamic covalent bonds include but are not limited to imine formation, [42] Diels-Alder cycloaddition, [43] thiol-disulfide exchange, [44][45][46][47] urea/urethane formation or exchange, [48][49][50][51][52] olefin metathesis, [53][54][55] dissociation-association of the C-ON bond of alkoxyamines, [56] transesterification, [57][58][59][60] and disulfide reversible reaction. [61,62] These dynamic bonds are incorporated in the main-chain or side-chains of the polymers.…”

NIR Light Stimulated Self‐Healing Reduced Tungsten Oxide/Polyurethane Nanocomposite Based on the Diels−Alder Reaction

“…[ 10–12 ] It can persist in chemical conditions for long time, external force during processing condition, such as thermal effect inevitably damages that lead to fractures and then the formation of microcracks. [ 13 ] Consequently, these cracks decrease the performance of the material and provide a channel to propagate chemical corrosion that shortens the lifetime of the material. The development of polyurethane material with self‐healing abilities is one of the most effective techniques to overcome this problem.…”

“…The development of polyurethane material with self‐healing abilities is one of the most effective techniques to overcome this problem. [ 13 ] For example, the Yubin group has reported new type of polyurethane from crosslinking a Diels‐Alder (DA) reaction with bismaleimide from isocyanate‐terminated pre‐polymer and furfuryl amine (FA), which showed an initial self‐healing tensile strength of 13.5 MPa and healing tensile strength of 12.2 MPa at 125 °C. [ 14 ] A new copper (II)‐dimethylglyoxime‐polyurethane composite was also synthesized and exhibited an initial maximum self‐healing and healing tensile strengths at room temperature of 14.8 and 13.8 MPa, respectively.…”