Highly Efficient, Environmentally Friendly Lignin-Based Flame Retardant Used in Epoxy Resin

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Chemistry

Background:

• Epoxy resins (EP) are widely used but pose fire risks.
• Developing effective flame retardants with reduced environmental impact is crucial.
• Lignin biomass offers a sustainable source for novel material development.

Purpose of the Study:

• To synthesize and characterize novel lignin-based flame retardants (Lig) with enhanced flame retardancy and smoke suppression.
• To incorporate these Lig into epoxy resins (EP) to create Lig/EP composites.
• To investigate the flame retardancy and smoke suppression mechanisms.

Main Methods:

• Lignin biomass was modified with functional groups containing nitrogen (N) and phosphorus (P).
• Lignin-based flame retardants (Lig) were compounded with epoxy resin (EP) at fixed ratios.
• Flame retardancy was assessed using UL-94 tests.
• Smoke suppression was evaluated by measuring total heat release and smoke production.
• Material characterization included SEM and Raman spectroscopy.

Main Results:

• A lignin-based flame retardant (Lig-F) with high phosphorus content demonstrated superior performance.
• The Lig-F/EP composite achieved a V-0 rating in the UL-94 test.
• Total heat release and smoke production were reduced by 46.6% and 53%, respectively.
• Analysis supported proposed mechanisms for flame retardancy and smoke suppression.

Conclusions:

• Modified lignin is a viable precursor for high-performance flame retardants.
• Lignin-based flame retardants offer excellent flame retardancy and smoke suppression for epoxy resins.
• This study presents a sustainable approach for developing advanced flame-retardant materials.