Hardening process and properties of an epoxy resin with bio-based hardener derived from furfural

The development of bio-based plastics is an important research area because of its contribution to environmental preservation. Herein, we evaluated the properties of a bio-based epoxy resin synthesised using 2,2-bis(4-glycidyloxyphenyl) propane as the epoxy monomer and oxabicyclodicarboxylic anhydride (OBCA) as a bio-based hardener derived from furfural. The major hardening process of the resin at 130 degrees C, manifested in an exponential increase in the storage modulus, was complete within an hour, which was longer than that for a commercially available petroleum-based epoxy resin hardened using cis-cyclohexane dicarboxylic anhydride (CDCA). This indicated that OBCA was less reactive than CDCA, which has a similar structure. The bio-based epoxy resin showed excellent transparency in the visible light region and was thermally stable, with 5% weight loss at temperatures exceeding 270 degrees C. Glass transition temperatures were above 100 degrees C, and mechanical properties were moderately better than those of the commercially available epoxy resin. Moreover, the bio-based carbon content ranged from 21% to 53%, depending on the amount of OBCA added. Thus, the bio-based OBCA is a good hardener for a bio-based epoxy resin that can be used as a value-added material in industrial applications.