There is a huge requirement of elastomers for use in tires, seals, and shock absorbers every year worldwide. In view of a sustainable society, the next generation of elastomers is expected to combine outstanding healing, recycling, and damage‐tolerant capacities with high strength, elasticity, and toughness. However, it remains challenging to fabricate such elastomers because the mechanisms for the properties mentioned above are mutually exclusive. Herein, the fabrication of healable, recyclable, and mechanically tough polyurethane (PU) elastomers with outstanding damage tolerance by coordination of multiblock polymers of poly(dimethylsiloxane) (PDMS)/polycaprolactone (PCL) containing hydrogen and coordination bonding motifs with Zn2+ ions is reported. The organization of bipyridine groups coordinated with Zn2+ ions, carbamate groups cross‐linked with hydrogen bonds, and crystallized PCL segments generates phase‐separated dynamic hierarchical domains. Serving as rigid nanofillers capable of deformation and disintegration under an external force, the dynamic hierarchical domains can strengthen the elastomers and significantly enhance their toughness and fracture energy. As a result, the elastomers exhibit a tensile strength of ≈52.4 MPa, a toughness of ≈363.8 MJ m−3, and an exceptional fracture energy of ≈192.9 kJ m−2. Furthermore, the elastomers can be conveniently healed and recycled to regain their original mechanical properties and integrity under heating.

Kinetics of II to I polymorphic transformation in isotactic polybutene-1 (PB-1) and its annealing temperature and time dependencies have been investigated by means of differential scanning calorimetry and in situ wide-angle X-ray diffraction techniques. The PB-1 samples were isothermally crystallized into metastable form II crystalline modification followed by annealing at a lower temperature (T l) and at a higher temperature (T h) subsequently or at a single temperature (T s) to promote polymorphic transition from form II to I. This solid-to-solid phase transition was shown to be a two-step process including nucleation and growth suggested by the result that more form I was obtained after being annealed at T l and T h than annealed at T s for the same period. Annealing at T l benefits nucleation due to internal stress induced by unbalanced shrinkage of amorphous and crystalline phases because of their different thermal expansion coefficients, while annealing at T h is beneficial to growth owing to rapid segmental diffusion at that temperature. At a given annealing time at T l (t l) and at T h (t h), and fixing one of temperatures between T l and T h, it shows a maximum in the transformation-temperature profile that can be correlated with the optimal temperature for nucleation or growth. The phase transition was efficiently accelerated with the increase of isothermal crystallization temperature. Such dependency can be understood as a result of higher internal stress built up during cooling from higher isothermal crystallization temperature to T l. Our results decomposed the polymorphic transition into nucleation and growth for the first time providing a simple and effective way for rapid transition of form II to I in PB-1.