A highly transparent and self-healing elastomer based on dynamically reversible heterocyclic interactions with enhanced toughness and outstanding rolling reliability

Abstract

A highly flexible elastomer for rollable displays was developed through the incorporation of reversible heterocyclic interactions. Functional heterocyclic pendant moieties were integrated into the polymeric chains within a conventional elastomer, facilitating dynamically reversible internal interactions via intensified hydrogen bonding. This approach significantly enhanced the performance of the resulting elastomer by optimizing its internal network structure. It exhibited excellent optical properties, including visible light transmittance over 91 %, a yellow index below 2, a haze under 1 %, and substantial thermal stability. Moreover, it effectively addressed the traditional trade-off between mechanical and self-healing properties in typical self-healing materials. It also achieved rapid and complete self-healing and a toughness value four times greater than a reference elastomer lacking heterocyclic groups. Notably, the developed elastomer exhibited outstanding durability, enduring over 10,000 rolling and unrolling cycles without mechanical failure, which underscores its superior rolling reliability. These properties are attributed to a unique internal network structure reinforced by reversible and intensified hydrogen bonding within the matrix. To provide further insights into enhanced mechanical strength, self-healing performance, and rolling reliability, a mechanism was proposed and analyzed using both small molecular and polymeric model systems. This analysis highlights the critical role of the heterocyclic interactions in forming a robust yet dynamically adaptable network.