High-Performance, Light-Stimulation Healable, and Closed-Loop Recyclable Lignin-Based Covalent Adaptable Networks

Xiaozhen Ma; Xiaolin Wang; Honglong Zhao; Xiaobo Xu; Minghui Cui; Nathan E Stott; Peng Chen; Jin Zhu; Ning Yan; Jing Chen

doi:10.1002/smll.202303215

High-Performance, Light-Stimulation Healable, and Closed-Loop Recyclable Lignin-Based Covalent Adaptable Networks

Small. 2023 Oct;19(40):e2303215. doi: 10.1002/smll.202303215. Epub 2023 Jun 3.

Authors

Xiaozhen Ma^{1

2}, Xiaolin Wang¹, Honglong Zhao^{1

2}, Xiaobo Xu^{1

3}, Minghui Cui^{1

4}, Nathan E Stott¹, Peng Chen^{1

2}, Jin Zhu^{1

2}, Ning Yan⁵, Jing Chen^{1

2}

Affiliations

¹ Key Laboratory of Bio-based Polymeric Materials Technology and Application of Zhejiang Province, Laboratory of Polymers and Composites, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China.
² University of Chinese Academy of Sciences, Beijing, 100039, China.
³ School of Materials Science and Chemical Engineering, Ningbo University, Ningbo, Zhejiang, 315211, China.
⁴ School of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang, Liaoning, 110142, China.
⁵ Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5, Canada.

PMID: 37269200
DOI: 10.1002/smll.202303215

Abstract

In this work, high-performance, light-stimulation healable, and closed-loop recyclable covalent adaptable networks are successfully synthesized from natural lignin-based polyurethane (LPU) Zn²⁺ coordination structures (LPUxZy). Using an optimized LPU (LPU-20 with a tensile strength of 28.4 ± 3.5 MPa) as the matrix for Zn²⁺ coordination, LPUs with covalent adaptable coordination networks are obtained that have different amounts of Zn. When the feed amount of ZnCl₂ is 9 wt%, the strength of LPU-20Z9 reaches 37.3 ± 3.1 MPa with a toughness of 175.4 ± 4.6 MJ m^-3 , which is 1.7 times of that of LPU-20. In addition, Zn²⁺ has a crucial catalytic effect on "dissociation mechanism" in the exchange reaction of LPU. Moreover, the Zn²⁺ -based coordination bonds significantly enhance the photothermal conversion capability of lignin. The maximum surface temperature of LPU-20Z9 reaches 118 °C under the near-infrared illumination of 0.8 W m^-2 . This allows the LPU-20Z9 to self-heal within 10 min. Due to the catalytic effect of Zn²⁺ , LPU-20Z9 can be degraded and recovered in ethanol completely. Through the investigation of the mechanisms for exchange reaction and the design of the closed-loop recycling method, this work is expected to provide insight into the development of novel LPUs with high-performance, light-stimulated heal ability, and closed-loop recyclability; which can be applied toward the expanded development of intelligent elastomers.

Keywords: Zn2+ coordination bonds; closed-loop recovery; high performance; light-controlled healable; unmodified lignin.

Abstract

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