M.S. Chemical Engineering
Henry M. Rowan College of Engineering
Army Research Laboratory
Epoxy resins; Green chemistry; Lignin
Lignin is a natural and abundant renewable material composed of crosslinked phenylpropenyl units that when strategically depolymerized could potentially yield renewable bio-based aromatic building blocks for applications in high-performance thermosetting epoxy resins. Vanillyl alcohol, a lignin derived aromatic diol, is a potential platform chemical for the production of renewable bisphenols and epoxy thermosets. A new bio-based bisphenol (bisguaiacol) was synthesized via electrophilic aromatic condensation of vanillyl alcohol and guaiacol, from which diglycidyl ether of bisguaiacol (DGEBG) was prepared via epoxidation with epichlorohydrin.The thermomechanical properties of DGEBG blended with a commercial BPA-based epoxy resin and cured with a diamine were investigated via dynamic mechanical analysis (DMA). In addition, two bio-based diepoxy monomers were synthesized from vanillyl alcohol (DGEVA) and gastrodigenin (DGEGD) and characterized via 1H-NMR, 13C-NMR, FTIR, MS, and GPC. Vanillyl alcohol based epoxy resins bear a methoxy group covalently bonded to the aromatic ring ortho to the glycidyl ether group. The thermomechanical properties of cured DGEVA and DGEGD thermosets were compared to those of the cured DGEBG and commercially available thermosets to determine the effect of the methoxy moiety. DMA results indicate that the presence of the methoxy lowers the glass transition temperature (Tg), yet increases the storage modulus (E') at 25 deg. C in cured epoxy-amine systems.
Hernandez, Eric, "Synthesis and characterization of vanillyl alcohol based thermosetting epoxy resins" (2015). Theses and Dissertations. 458.