Lignin-based composites with enhanced mechanical properties by acetone fractionation and epoxidation modification

Area of Science:

• Materials Science
• Polymer Chemistry
• Biotechnology

Background:

• Epoxy resins are vital industrial materials due to their superior chemical and mechanical properties.
• Lignin, a renewable resource from lignocelluloses, remains underutilized due to structural complexity and heterogeneity.
• Developing sustainable alternatives to petroleum-based polymers is crucial for environmental protection.

Purpose of the Study:

• To valorize industrial alkali lignin into environmentally friendly, bio-based epoxy thermosetting materials.
• To investigate the potential of epoxidized lignin as a substitute for petroleum-based chemicals in epoxy formulations.
• To contribute to a circular bioeconomy through sustainable bioplastics development.

Main Methods:

• Industrial alkali lignin was epoxidized and used to substitute bisphenol A diglycidyl ether (BADGE) in varying proportions.
• Thermosetting epoxies were fabricated by cross-linking the epoxidized lignin-BADGE mixtures.
• The mechanical properties, including tensile strength and elongation, of the resulting thermosets were evaluated.

Main Results:

• The fabricated thermosetting resins exhibited enhanced tensile strength (4.6 MPa) and elongation (315.5%) compared to conventional BADGE polymers.
• Successful incorporation of epoxidized lignin into epoxy formulations was achieved.
• The study confirmed the feasibility of using lignin for creating high-performance bioplastics.

Conclusions:

• This research presents a practical method for lignin valorization into sustainable bioplastics.
• The developed bio-based epoxy thermosetting materials offer a promising low-carbon alternative to traditional polymers.
• The findings support the advancement of a circular bioeconomy by utilizing renewable resources for material production.