Lignin-Sourced Aromatics for Biodegradable Flexible Copolyesters Mimicking Poly(Butylene Adipate-co- Terephthalate)

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Materials

Background:

• Poly(butylene adipate-co-terephthalate) (PBAT) is a widely used biodegradable polyester.
• Current PBAT production relies on fossil-based terephthalates, raising environmental concerns.
• Developing sustainable alternatives is crucial for reducing reliance on fossil fuels.

Purpose of the Study:

• To synthesize novel PBAT-mimicking copolyesters using lignin-sourced aromatic monomers.
• To evaluate the environmental impact, including greenhouse gas emissions and solvent usage.
• To assess the thermal properties, biodegradation rates, and oxygen barrier performance of the synthesized copolyesters.

Main Methods:

• Synthesis of two series of PBAT-mimicking copolyesters.
• Incorporation of lignin-sourced aromatic monomers (methyl 4-(2-hydroxyethoxy) vanillate and methyl 4-(2-hydroxyethoxy) benzoate) with aliphatic dimethyl adipate and 1,4-butanediol.
• Life cycle assessment for greenhouse gas emissions and evaluation of solvent usage.
• Characterization of thermal stability, glass transition temperature, and crystallinity.
• Aerobic biodegradation experiments over 90 days.
• Measurement of oxygen gas barrier properties of copolyester films.

Main Results:

• Successfully synthesized PBAT-mimicking copolyesters with tunable properties.
• Demonstrated comparable or enhanced biodegradation rates versus PBAT.
• Achieved improved oxygen gas barrier properties compared to PBAT.
• Life cycle assessment indicated reduced environmental impact from monomer synthesis.

Conclusions:

• Lignin-derived copolyesters offer a promising sustainable alternative to conventional PBAT.
• These materials exhibit favorable biodegradation and barrier properties for flexible food packaging.
• The study highlights the potential of bio-based monomers in creating high-performance, eco-friendly polymers.