Functionalized lignin nanoparticles for producing mechanically strong and tough flame-retardant polyurethane...

Area of Science:

• Polymer Science and Engineering
• Materials Chemistry
• Green Chemistry

Background:

• Growing demand for sustainable and high-performance polyurethane elastomers (PUE).
• Need for effective flame retardants that do not compromise mechanical properties.
• Limitations of traditional flame retardants and lignin additives in PUE.

Purpose of the Study:

• To develop novel nano functionalized lignin nanoparticles (Nano-FL) as green additives for PUE.
• To enhance both mechanical performance and flame retardancy of PUE.
• To investigate the compatibility and effectiveness of Nano-FL in a PUE matrix.

Main Methods:

• Mild grafting reactions and ultrasound method for Nano-FL synthesis.
• Incorporation of Nano-FL into PUE matrix as crosslinking agents and flame retardants.
• Evaluation of mechanical properties, limiting oxygen index, UL-94 rating, and Cone Calorimetry Test (CCT).

Main Results:

• Nano-FL exhibited good compatibility and dispersibility in PUE.
• PUE/Nano-FL composites showed enhanced tensile properties compared to neat PUE.
• 10 wt% Nano-FL addition resulted in a limiting oxygen index of 29.8% and UL-94 V-0 rating.
• CCT revealed reduced heat release, smoke production, and improved char residue oxidation resistance.

Conclusions:

• Novel Nano-FL acts as an effective green additive for PUE.
• Nano-FL enhances mechanical strength and flame retardancy without compromising material integrity.
• Developed Nano-FL shows significant promise for improving a wide range of polymer applications.