Preparation and Characterization of Fully Furan-Based Renewable Thermosetting Epoxy-Amine Systems

Fully furan-based epoxy/amine thermosetting materials are prepared and investigated using a furanyl epoxy monomer, 2,5-bis[(2-oxiranylmethoxy)methyl]-furan (BOF), and two furanyl amine hardeners, 5,5-methylenedifurfurylamine (DFDA) and 5,5-ethylidenedifurfirylamine (CH3-DFDA). These furan-based thermosets have shown promising glass transition temperatures (62 and 69 degrees C, respectively, using tan delta) and room temperature storage moduli (approximate to 3.5 GPa). The BOF/CH3-DFDA sample is exhibited higher T-g than the BOF/DFDA system due to the presence of an additional methyl group in CH3-DFDA. Used as curing agents for DGEBA, DFDA and CH3-DFDA have shown excellent performance with resulting T(g)s well above 120 degrees C. Onset degradation temperature of the fully furan-based samples is observed around 270 degrees C with high char yields (approximate to 40 wt%) at 750 degrees C in argon. Based on their thermal and mechanical properties, the renewable fully furan-based thermosets are found suitable for coating, adhesive, and composite applications, and are therefore potential replacements for incumbent systems.