Synthesis and Characterization of Furanyl Based Thermosetting Polymers with Advanced Thermal and Mechanical Properties

Renewable alternatives to petroleum-based thermosetting materials have elicited increasing interest due to their potential positive economic and ecological impacts. New materials should mimic the rigid, phenyl structures of incumbent high-performance thermosetting resins. Furans derived from cellulose and hemicellulose are promising candidates for phenyl replacements. Synthesis of furanyl based diepoxy monomers is challenging, and direct thermal and mechanical property comparisons of thermosetting materials prepared using furanyl and phenyl epoxy monomer analogues are required. In this work, analogous furanyl and phenyl based diepoxy monomers are synthesized, and thermosetting polymers are prepared using amine hardeners. A structure-property study shows that furanyl based polymers possess improved glass transition temperature (DT_g = 16 °C), glassy modulus (DE’ = 0.60 GPa) and fracture toughness property (DG_1c = 0.78 KJ/m²) relative to their phenyl analogues. Epoxy-amine cure kinetics study of these analogous systems is conducted, and different influences of furanyl and phenyl building blocks on the cure behaviors suggest hydrogen bonding potentially affect not only the processing characteristics, but also the thermal and mechanical properties of furanyl based epoxy systems relative to phenyl analogues. Thus, the furanyl ring has been demonstrated to be a promising building block for renewable high-performance epoxy resins as replacements of phenyl based epoxy incumbents.