Chemoenzymatic cascade reaction for the production of furan-based polyesters with different thermal performance

The oxidation products of 5-hydroxymethylfurfural (HMF) have been classified as favorable bio-source building blocks and employed to the production of polymers. Herein, a chemoenzymatic cascade reaction was proposed for the production of furan-based polyesters. Ruthenium lignosulphonate (Ru-LigS) was prepared using a facile hydrothermal process for HMF oxidation. The synergistic effect between ruthenium and sodium lignin sulfonate promoted this process, resulting in obvious improvement in catalytic performance. After separation, two furan-based polyesters were prepared through enzymatic polymerization by using two HMF oxidation products as the monomers. The minor difference in structure afforded a significant difference in the thermal properties of these two polyesters. Self-polymerized polyester derived from 5-hydroxymethyl-2-furancarbonxylic acid (HMFCA) was amorphous along with a glass transition temperature as low as −43.9 °C, demonstrating excellent cold resistance performance. Instead, the polyester polymerized by 2,5-furandicarboxylic acid (FDCA) and 2,5-bis(hydroxymethyl)furan (BHMF) was crystalline and possessed good thermodynamic properties. This study presented sustainable chemical conversion processes for both oxidizing HMF using highly active biomacromolecule catalysts and producing valuable furan-based polyesters.