New Kind of Lignin/Polyhydroxyurethane Composite: Green Synthesis, Smart Properties, Promising Applications, and Good...

Area of Science:

• Polymer Science
• Materials Science
• Green Chemistry

Background:

• Polyurethanes (PUs) are versatile polymers, but traditional synthesis often involves hazardous isocyanates.
• Developing sustainable and biobased alternatives to conventional PUs is crucial for environmental protection.
• Lignin, a byproduct of the paper industry, offers a renewable resource for material development.

Purpose of the Study:

• To synthesize a novel lignin-containing polyhydroxyurethane (LPHU) composite.
• To establish an isocyanate-free, solvent-free, and catalyst-free preparation method.
• To investigate the properties and potential applications of the resulting LPHU materials.

Main Methods:

• Preparation of LPHU using bis(6-membered cyclic carbonate) (BCC), dimer fatty diamine, and lignin.
• Characterization of the dual network structure (dynamic covalent and hydrogen bonding).
• Evaluation of mechanical strength, thermal stability, reprocessability, recyclability, shape memory, and self-healing properties.

Main Results:

• Successful synthesis of LPHU via a green, isocyanate-free route.
• LPHU materials exhibit a dual network structure.
• Demonstrated superior mechanical strength, high thermal stability, excellent reprocessability/recyclability, and smart properties (shape memory, self-healing).

Conclusions:

• LPHU represents a novel, sustainable biobased material with a unique dual network structure.
• The developed isocyanate-free method offers an environmentally friendly approach to PU/lignin composites.
• LPHU shows promise for applications in smart packaging and high-performance electromagnetic shielding materials.