UGA NMI Researchers test lignin-derived semiaromatic poly(ether ester)s

In the search for alternative biobased feedstocks for plastic applications, researchers at the UGA New Materials Institute synthesized and characterized monomers derived from lignin, the most abundant source of natural aromatics. The origin of lignin directly influences its molecular structure, and thus composites and blends that directly use lignin have shown performance inconsistencies—which led the team to crack lignin into monomers for polymer synthesis. 

Nine polyesters made from AB monomers that can be derived from lignin were tested for this study including phloretic, coumaric and ferulic acids, and similar derivatives. Testing included monomer and polymer synthesis, thermal analysis, mechanical characterization, gel content, rheological characterization and chemical recycling. 

The synthesis was done through sustainable, high-yield reactions that could be produced at a scale of greater than 50 grams. The characterization included thermal and mechanical properties, which showed great thermal stability and varying mechanical properties. Thermal stability allows the polyesters to be processed using melt extrusion and injection molding. The nine polyesters were easily chemically recycled to monomer in high yield. 

The coauthors for this study are Ryan K. Maynard, Kush G. Patel, Huiming Wu, Frida C. Knudsen, Imrie C. Ross, DeMichael D. Winfield and Jason J. Locklin. All are members of the Locklin Group, led by Jason Locklin, who also serves as director of the UGA New Materials Institute.  “Structure−Property Relationships of Lignin-Derived Semiaromatic Poly(ether ester)s” was published recently in the journal Macromolecules.