Synthesis and Characterization of Biobased Polyesters Derived from Vanillin-based Schiff Base and Cinnamic Acid Derivatives

Renewable resources-based homo- and copolyesters were prepared from novel vanillin-based Schiff base and biobased cinnamic acid derivatives by transesterification. Chemical structures of the Schiff base and resulting polyesters were confirmed by FT-IR, 1H NMR, and 13C NMR. Glass-transition temperatures of polymers were determined by DSC and showed over 100 °C. Photoluminescence properties were investigated for the Schiff base and polyesters. For polymers, broader emission spectra were observed compared with monomers, which probably originated from intramolecular charge transfer in each monomeric unit.