Synthesis and Characterization of Biobased Polyesters with Anthraquinones Derived from α‐Resorcylic Acid

ABSTRACT In recent years, biobased polymers have attracted attention as eco‐friendly materials for reducing fossil resource consumption. In this study, two types of 3,7‐dialkoxy‐1,5‐dihydroxyanthraquinones (RA diols) were synthesized from α‐resorcylic acid, a metabolite and oxide of alkylresorcinols found in rye bran, and polymerized with four diacyl chlorides via interfacial polymerization to investigate the effects of main and side chains on the solubility and physical properties of polyesters containing anthraquinone substituents. The solubility of RA polyesters was strongly influenced by the dicarboxylate units, and those containing aromatic dicarboxylate units exhibited high solvent resistance. The thermal properties of RA polyesters were affected by the rigidity of both the alkoxy side chains and dicarboxylate units. The RA polyester with octyloxy side chains and 4,4’‐oxybis(benzoate) (OB) units demonstrated excellent thermal properties and formability. To design RA polyesters with high solvent resistance and formability, aromatic dicarboxylate units with flexible structures, such as OB unit, are recommended.