Synthesis of Biomass-Based Monomers from Biomass-Based Furfural for Polyesters and Evaluation of Their Biomass Carbon Ratios

Commercially available furfural has been produced from hemicellulose derived from inedible-biomass-based resources, and furfural has been converted into commercially available furan by decarboxylation. These heterocyclic compounds are important chemicals for the production of biomass-based monomers. Oxidation of furfural gave a mixture of maleic acid and FA. These were hydrogenated to give succinic acid. Dimethyl succinate was synthesized from FA by esterification and hydrogenation. These chemicals are useful as biomass-based monomers for biomass-based plastics. Fully biomass-based poly(butylene succinate) (PBS) was obtained by polycondensation of biomass-based 1,4-butanediol and biomass-based succinic acid or dimethyl succinate. Succinic anhydride (SAn) and tetrahydrofuran (THF) were also synthesized from furfural. Fully biomass-based poly(butylene oxide-co-butylene succinate) was obtained by ring-opening polymerization of biomass-based SAn and THF. Partially biomass-based poly(butylene terephthalate) was obtained by polycondensation of biomass-based 1,4-butanediol and petroleum-based terephthalic acid. The biomass carbon ratio calculated from 14C concentrations measured by accelerator mass spectroscopy verified that the PBS obtained in this study contained only biomass carbon. The polycondensation of biomass-based 1,4-butanediol and petroleum-based terephthalic acid or dimethyl terephthalate gave partially biomass-based poly(butylene terephthalate), which is an engineering plastic.