Photothermal-responsive lignin-based polyurethane with mechanically robust, fast self-healing, solid-state plasticity...

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Materials

Background:

• Growing concerns over petrochemical resource depletion and environmental pollution necessitate sustainable material alternatives.
• Lignin, a natural biomass component, offers a promising renewable resource for developing functional materials.

Purpose of the Study:

• To develop a photothermal-responsive lignin-based polyurethane (DLPU).
• To impart self-healing and shape-shifting capabilities to the DLPU through controlled bond dynamics.

Main Methods:

• Incorporation of lignin and oxime-carbamate bonds into a polyurethane network.
• Utilizing near-infrared (NIR) irradiation to trigger photothermal effects.
• Characterization of mechanical properties, photothermal conversion efficiency, and responsive behaviors.

Main Results:

• The DLPU demonstrated excellent mechanical strength (30.2 MPa) and toughness (118.7 MJ·m⁻³).
• High photothermal conversion efficiency (54.4%) enabled efficient self-healing (96.0% tensile strength recovery) and shape-memory effects (98.8% fixity, 95.3% recovery).
• NIR irradiation activated reversible dynamics of oxime-carbamate and hydrogen bonds, leading to photocontrolled plasticity and shape-shifting.

Conclusions:

• The developed DLPU is a multi-functional, responsive material with significant potential for high-value lignin utilization.
• This research offers a sustainable pathway for creating advanced polyurethanes with tunable self-healing and shape-memory functionalities.