Biomimetic supramolecular polyurethane with sliding polyrotaxane and disulfide bonds for strain sensors with wide sensing range and self-healing capability

To prolong the service life of flexible electronic materials, polymeric matrixes with excellent self-healing capability and integrated mechanical properties are highly desirable, but the balance between the self-healing capability and mechanical properties is a grand challenge. Here, polyrotaxanes as sliding crosslinkers and dynamic disulfide bonds are incorporated into the main chains of polyurethane (PU) via one-pot synthesis, which endows the PU with polydisperse hard/soft segments, high density of self-healing points and energy dissipation. Based on this judicious molecular design, the PU elastomers exhibit exceptional mechanical properties, such as high stretchability (1167 % with a tensile strength of 3.49 MPa), high fracture energy (20,775 J m(-2)) and high puncture energy (200.70 mJ). Moreover, due to the presence of dynamic reversible hydrogen and disulfide bonds, the elastomer could achieve stress and strain repair efficiencies of 93.98 % and 99.21 % at 100 degrees C within 1 h, respectively. The above-mentioned superiorities enable the bioinspired strain sensors to possess a large sensing range (similar to 596 %), high sensitivity (similar to 79.98), short response time (similar to 128 ms), along with excellent reliability and self-healing ability. Besides, the strain sensor exhibits remarkable recyclability and prominent reprocessability, which nicely solves the pollution by discarded electronics. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

In this study, the incorporation of sliding crosslinkers and dynamic disulfide bonds into the main chains of polyurethane (PU) using a one-pot synthesis method provides the PU with exceptional mechanical properties and self-healing capability. The PU elastomers demonstrate high stretchability, fracture energy, and puncture energy. Furthermore, the presence of dynamic reversible hydrogen and disulfide bonds allows the elastomer to achieve stress and strain repair even at high temperatures.