Fully biobased lignin-functionalized elastomers enabling UV shielding, photothermal conversion, and thermoelectric...

With the rapid rise of the flexible electronics industry, the demand for flexible functional materials in emerging fields such as wearable devices has upgraded from single performance to functional integration and green sustainability. In this work, alkali lignin was modified with thioctic acid (TA) and selected as the macromonomer. A series of fully biobased lignin-graft-poly (tetrahydrofurfuryl acrylate-co-isobornyl acrylate) (Lignin-g-P(THFA-co-IBOA)) copolymers was prepared by regulating the feeding ratio and lignin content via conventional radical polymerization. The resulting lignin-based copolymers exhibit tunable mechanical properties, excellent UV shielding performance, and outstanding photothermal conversion capacity. When integrated into a thermoelectric conversion system, the Lignin-g-P(THFA-co-IBOA) copolymer can serve as a high-efficiency flexible photothermal power generation module, making it well suited for applications in wearable devices and intelligent terminals. Through a simple and efficient polymerization process, this study not only achieves the high-value utilization of lignin but also overcomes the technical challenges posed by its heterogeneous structure and poor processability. This approach offers a new pathway toward the green and low-cost production of flexible electronic materials, while simultaneously providing theoretical and technical insights for the value-added application of lignin resources, thereby contributing to the sustainable development of the flexible electronics industry.