Synthesis of lignin-based elastomers via ARGET ATRP: Exceptional mechanical strength, adhesion, and self-repair properties.

In this study, ARGET ATRP method was employed to graft two functional monomers from lignin, resulting in the synthesis of a series of Lignin-graft-poly(lauryl methacrylate-co-cyclohexyl methacrylate) (Lignin-g-P(LMA-co-CMA)) copolymers with varying feed ratios and lignin content. The results demonstrate that by varying the feed ratios of the two monomers, the glass transition temperature of lignin-based elastomers can be finely tuned. Importantly, the introduction of lignin and CMA imparts outstanding mechanical properties to the lignin-based elastomers, with a maximum tensile strength reaching 20.13 MPa. The elastic recovery rate of the lignin-based elastomers was exceptional, with the elastic recovery coefficient (ER) of Lignin0.52-PLMA500 exceeding 90 %. Adhesion tests on various substrates revealed the remarkable adhesion properties of these copolymers. In particular, Lignin0.52-PLMA500 exhibited strong adhesion on both iron plate and glass substrate, with adhesion strengths of 2.23 MPa and 2.33 MPa, respectively. Notably, Lignin0.52-PLMA500 demonstrated significant self-healing ability after damage. Furthermore, the lignin-based elastomer exhibited exceptional ultraviolet absorption performance. In conclusion, the incorporation of lignin opens up a novel pathway for the development of high-strength and tough lignin-based elastomers. However，more effort still needs to be paid for increasing the adhesive properties aiming to explore more potential application field.