Polymer, 2019, pp. 122003
DOI:10.1016/j.polymer.2019.122003
Abstract
Achieving good transparency, high strength and superior extensibility simultaneously in autonomic self-healing elastomers remains challenging and fascinating. Herein, a complementary design strategy of combining densely distributed multiple hydrogen bonds (H bonds) and loosely packed spacer units in supramolecular elastomer was reported to address the inherent contradiction of robust strength and room temperature self-healing. The chemical structure can be tuned to achieve a good compromise between the mechanical properties and self-healing efficiency. The representative elastomers can achieve robust strength (6.81 MPa), high extensibility (2520%) and superior toughness with the dissipated energy up to 63.7 MJ/m3. Moreover, this elastomer is capable of recovering mechanical fractures and routine scratches with the self-healing efficiency up to 90%, which are comparable to that of room-temperature self-healable counterparts. Spacer units with steric hindrance effect can facilitate segmental motions and dynamic changes of H-bonds. Meanwhile, the randomly distributed multiple H bonds crosslinking such spacers contribute to the good mechanical performance and intriguing self-healing. In contrast to previous reports, this strategy provides an uncomplicated and cost-effective route to prepare robust elastomers that can self-heal at room temperature without any need of external assistance.
