Stretchable and Sustainable Poly(thioctic Ester) Elastomers Catalyzed by Lithium Salt for Ionic Sensors and Thermoelectrics

Abstract The sustainability and recyclability challenges of ionotronic devices have become a growing global concern. This paper presents a novel thermal polymerization method for processing thioctic esters (TEs) to prepare biobased and sustainable ionic conductors, i.e., poly(thioctic esters) (PolyTEs), which are catalyzed by lithium salts. This synthetic method is efficient, solvent‐free, and applicable to the polymerization of various TEs at both room temperature and high temperatures without an inert atmosphere. Lithium salts simultaneously act as TE polymerization catalysts and conductive elements in the resulting ionic conductors. The synthesized ionically conductive elastomers exhibit excellent ductility, high conductivity, intrinsic self‐healing properties, strong adhesion ability, and ideal recyclability. The application of the synthesized PolyTE as an ionic sensor is further demonstrated. PolyTE‐based sensors are applied to sensitively and durably detect strain, compression, and temperature and have shown significant potential for applications in ionic devices and electronics. In addition, the feasibility of using a PolyTE to prepare ionic thermoelectric capacitors (ITECs) is demonstrated. This study offers a novel perspective and synthesis approach for the solvent‐free thermal polymerization of TEs while simultaneously advancing the applications of multifunctional biobased materials in ionotronic devices.