The properties and suitability of commercial bio-based epoxies for use in fiber-reinforced composites

Abstract

Environmental concerns about fiber composites are leading manufacturers to consider bio-based alternatives to petroleum-derived epoxies. Such a substitution is hindered by a lack of information, so commercially available bio-based epoxy systems have been compared, their mechanical properties measured, and fiber composites produced by vacuum infusion. Most high bio-based content resins for infusion use conventional curing agents. Bio-based content is generally added using Epicerol, but also other bio-based precursors. A diglycidyl ether of bisphenol A system produced using Epicerol achieves 20 % bio-based content, but achieves higher contents when Epicerol is used in diluents. Fully bio-based monomers can be deleterious to the mechanical properties and glass transition temperature (Tg), so are used sparingly. The most-promising systems (28 % to 43 % bio-based) compare well to conventional epoxies, possessing good strength, stiffness, toughness, and a reasonable Tg. These partially bio-based epoxies offer an immediate lower-carbon alternative for vacuum-infused composites in marine, sports equipment, and wind energy.