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

Abstract

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 °C, respectively, using tan delta) and room temperature storage moduli (≈3.5 GPa). The BOF/CH3-DFDA sample is exhibited higher Tg 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 Tgs well above 120 °C. Onset degradation temperature of the fully furan-based samples is observed around 270 °C with high char yields (≈40 wt%) at 750 °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. For the first time, fully furan-based epoxy/amine thermosetting materials are prepared and reported 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 thermosetting materials have shown promising glass transition temperatures (62 and 69 °C) and room temperature storage moduli (≈3.5 GPa).