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Published on: June 17, 2014
High-Performance, Light-Stimulation Healable, and Closed-Loop Recyclable Lignin-Based Covalent Adaptable Networks.
Xiaozhen Ma1,2, Xiaolin Wang1, Honglong Zhao1,2
1Key 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.
New lignin-based polyurethane (LPU) coordination networks exhibit high performance, light-stimulated self-healing, and closed-loop recyclability. Zinc (Zn2+) enhances mechanical properties and photothermal conversion, enabling rapid healing and efficient material recovery.
Area of Science:
- Materials Science
- Polymer Chemistry
- Sustainable Chemistry
Background:
- Developing high-performance, recyclable polymers is crucial for sustainable materials.
- Lignin, a natural polymer, offers a renewable resource for material synthesis.
- Covalent adaptable networks (CANs) provide dynamic and recyclable polymer structures.
Purpose of the Study:
- To synthesize high-performance, light-stimulated healable, and closed-loop recyclable covalent adaptable networks from lignin-based polyurethane (LPU) using Zn2+ coordination.
- To investigate the effect of Zn2+ on the mechanical properties, photothermal conversion, and self-healing capabilities of the LPU-based CANs.
- To explore the mechanism of the exchange reaction and establish a closed-loop recycling method for the developed materials.
Main Methods:
- Synthesis of lignin-based polyurethane (LPU) and its coordination with Zn2+ to form LPUxZy.
- Mechanical testing (tensile strength, toughness) of the synthesized materials.
- Photothermal conversion assessment under near-infrared illumination.
- Evaluation of light-stimulated self-healing and closed-loop recyclability in ethanol.
Main Results:
- LPU-20Z9, with 9 wt% ZnCl2, achieved a tensile strength of 37.3 ± 3.1 MPa and toughness of 175.4 ± 4.6 MJ m-3.
- Zn2+ significantly enhanced photothermal conversion, reaching 118 °C under 0.8 W m-2 NIR illumination, enabling self-healing within 10 minutes.
- The Zn2+-catalyzed exchange reaction allowed complete degradation and recovery of LPU-20Z9 in ethanol, demonstrating closed-loop recyclability.
Conclusions:
- High-performance, light-stimulated healable, and closed-loop recyclable covalent adaptable networks were successfully synthesized from lignin-based polyurethane and Zn2+ coordination.
- The Zn2+ coordination plays a critical role in enhancing mechanical properties, photothermal conversion, and facilitating efficient recycling.
- This study provides a pathway for developing advanced intelligent elastomers with improved sustainability and functionality.
