Composites composed of epoxy resins are high strength, yet lightweight alternatives to traditional metal components used in automotive, windmill, and electronics industries. Traditionally, epoxy resins are produced from petroleum-derived bisphenol A (BPA), which is epoxidized and cured with an amine or anhydride hardener. Unfortunately, BPA-based epoxy resins are derived from a non-sustainable resource and are not easily recycled, and BPA itself is a known endocrine disruptor. Lignin, a component of biomass with rigid aromatic structures, offers potential as a more sustainable and less toxic replacement for BPA in epoxy resins. When crude depolymerized lignin was used to produce epoxy resins, the resulting polymers exhibited low glass transition temperatures and moduli compared to commercial petroleum-based resins. In contrast, when individual lignin-derived model compounds were used as precursors for producing epoxy resins, the polymers had superior thermomechanical properties, comparable to commercial resins. Here we present for the first time the use of syringic acid, a product of catalytic depolymerization of lignin, as a precursor for producing biobased epoxy resins. Syringic acid was epoxidized and cured with an anhydride curing agent. We have examined the properties of epoxy resins derived from syringic acid alone, as well as from mixtures of lignin-derived model compounds. These studies have helped us understand how individual lignin monomers or their combinations impact epoxy resin properties and produce targeted epoxy resins with superior properties to petroleum derived resins.

Sustainable epoxy resins derived from syringic acid and mixtures of lignin monomers

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.