High strength, self-healing polyurethane elastomer based on synergistic multiple dynamic interactions in multiphase

Inspired by some biological phenomena, self-healing materials has been made great progress over the past decades. However, it is challenging to establish an adaptable strategy to achieve a good tradeoff between mechanical strength and self-healing ability. Herein, we reported a self-healing polyurethane elastomer (PPG-UPy-SS) with desirable mechanical performance and wonderful self-healing capacity via incorporating synergistic multiple dynamic interactions in multiphase. The 2-amino-5-(2-hydroxyethyl)-6-methylpyrimidin-4-ol (UPy) motif was introduced into the PPG segment to keep the mechanical performance profiting from the regular arrangement of hydrogen-bonding array and microphase separation benefited from π-π stacking of UPy dimers. 4-aminophenyl disulfide (APDS) was embedded into the loosely stacked amorphous region to increase the mobility of the chain segment to improve self-healing performance. The optimized sample PPG-UPy50%-SS50% possesses high tensile strength and fracture toughness of 18.2 MPa and 57.3 MJ m−3, and satisfactory self-healing efficiency of 99% and 96% (10 h at 80 °C), respectively.