Synthesis and Characterization of High-Performance, Bio-Based Epoxy-Amine Networks Derived from Resveratrol

Resveratrol is a sustainable and versatile bio-derived phenolic compound that has shown promise as a high glass-transition temperature (T-g), flame-resistant building block for thermoset networks. In this study, three components of epoxy thermoset resins were synthesized from resveratrol: trans-resveratrol trisepoxy (1), dihydroresveratrol trisepoxy (2), and a trifunctional amine, 4,4'-((5-(4-(4-aminophenoxy)phenethyl)-1,3-phenylene)bis(oxy))dianiline (4). The epoxy monomers were low melting solids (mp < 80 degrees C) or thick oils consisting of primarily monomeric trisepoxides. Toxicity testing of 4 revealed that it was not mutagenic and had a low LD50 of 560 mg/kg, an aquatic toxicity of >2000 mg/L, and no cytotoxicity up to its solubility limit. The epoxy monomers were cured with 4,4'-methylenedianiline (3) and 4 to produce four epoxy-amine networks (A-D). Networks C and D, prepared with the resveratrol-derived aniline, contained up to 52.6% bio-based material. The moisture uptake, thermal stability, and dry/wet thermomechanical properties of the networks were measured. The networks had T-g's as high as 285 degrees C, approximately 110 degrees C higher than networks based on petroleum-derived bisphenol A (BPA). In addition, the resveratrol networks had char yields as high as 51 and 46% in nitrogen and air, respectively, compared to ca. 15 and 5%, respectively, for BPA-based networks. Overall, this study shows the advantages of resveratrol-based epoxy and amine monomers as components of sustainable, low-toxicity, high-temperature resin systems.