Structure-Property Relationships of Lignin-Derived Semiaromatic Poly(ether ester)s

Semiaromatic polyesters derived from petroleum are an important class of polymers that encompass a wide variety of thermal and mechanical properties. Unfortunately, replacing the aromatic component with cost-competitive bioderived monomers is an ongoing challenge. This work describes the synthesis of nine different polyesters made from AB monomers that can be derived from lignin, starting with phloretic, coumaric, and ferulic acids and similar derivatives. The polyesters were synthesized at >50 g scale, and full characterization of the thermal, mechanical, and rheological properties is included. The polymers exhibit excellent thermal stability, a T _g range of 16-65 °C, tensile moduli ranging from 4.6 to 1200 MPa, and elongation at break ranging from 7.5% to greater than 3800%. To examine the effects of structural permutations among the polymer series, TTS master curves were constructed for seven polyesters using melt rheology. Properties such as packing length and characteristic ratio are described and compared among the series. Finally, it is demonstrated that these polyesters are easily chemically recycled to monomer in high yield.