A Visible Light-Responsive, Fast Room-Temperature Self- Healing, Mechanically Robust, Antibacterial Waterborne...

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Developing room-temperature self-healing polymers with high mechanical strength is challenging.
• Waterborne polyurethanes (WPUs) are desirable for their environmental friendliness.
• Existing WPUs often compromise mechanical properties for self-healing capabilities.

Purpose of the Study:

• To design a novel waterborne polyurethane (DMZWPU) with visible light-responsive, room-temperature self-healing, and antibacterial properties.
• To achieve a balance between robust mechanical performance and rapid self-healing ability.
• To explore the application of DMZWPU in leather finishing.

Main Methods:

• Molecular design incorporating triple dynamic bonds: diselenide, hydrogen, and Zn(II)-carboxylate coordination bonds.
• Fabrication of DMZWPU films and evaluation of mechanical properties (tensile stress, fracture toughness).
• Assessment of room-temperature self-healing efficiency under visible light and trace ethanol induction.
• Evaluation of antibacterial activity and application in leather finishing.

Main Results:

• The DMZWPU film exhibited a tensile stress of 40.32 MPa and fracture toughness of 119.29 MJ/m³.
• Over 85% of tensile stress was recovered within 2 hours at room temperature via dual induction.
• Achieved 100% sterilization rate within 24 hours due to selenium and zinc ions.
• DMZWPU coatings on leather demonstrated excellent folding resistance, wear resistance, and enhanced water/friction resistance.

Conclusions:

• The synergistic effect of triple dynamic bonds successfully balanced mechanical strength and self-healing efficiency.
• DMZWPU offers superior room-temperature self-healing performance compared to most reported polymers.
• The material shows significant potential for applications in coatings, particularly for leather finishing.