A novel bio-based anhydride curing agent for the synthesis of high-performance epoxy resin

ABSTRACT The continuous consumption of fossil resources and the resulting environmental pollution problems make the synthesis of polymers from renewable resources more and more attractive. Herein, a bio-based epoxy curing agent, 3,6-epoxide hexahydrophthalic anhydride (EHPA), was synthesized successfully from renewable furan and maleic anhydride by combining Diels-Alder and hydrogenation reactions and can cure diglycidyl ether of bisphenol A (DGEBA) to produce a sustainable thermosetting resin (EEP). Tensile properties and dynamic mechanical analysis show that EEP is a high-strength, high-toughness, and high-modulus material, showing higher glass transition temperature (201°C), tensile strength (104.51 MPa), and storage modulus (4.14 GPa) than those of epoxy thermosets (MEP) cured with the petroleum-based methyl tetrahydrophthalic anhydride (MeTHPA). Besides its high performance, EEP can be degraded via the cleavage of its ester bonds at mild conditions (150°C, 5 wt.% NaOH aqueous solution), making it an environmentally friendly alternative to petroleum-based epoxy resins. Our results provide a way to synthesize bio-based curing agents to fabricate high-performance and degradable epoxy resin polymers that are expected to be applied in the aerospace fields.