Synthesis of Epoxy Resins from Alcohol-Liquefied Wood and the Mechanical Properties of the Cured Resins

New wood-based epoxy resins were synthesized from alcohol-liquefied wood. Wood was first liquefied by the reaction with polyethylene glycol and glycerin. The alcohol-liquefied wood with plenty of hydroxyl groups were precursors for synthesizing the wood-based epoxy resins. Namely, the alcoholic OH groups of the liquefied wood reacted with epichlorohydrin under alkali condition with a phase transfer catalyst, so that the epoxy groups were put in the liquefied wood. The wood-based epoxy resins and the alcohol-based epoxy resins as reference materials were cured with polyamide amine. The glass transition temperature (Tg), the tensile strength, and the modulus of elasticity of the wood-based epoxy resin were higher than those of the alcohol-based epoxy resin. Also, the shear adhesive strength of the wood-based epoxy resin to steel plates was higher than those of the alcohol-based epoxy resins, which was equivalent to the level of petroleum-based bisphenol-A type epoxy resins. The higher Tg of the wood-based epoxy resin than that of the alcohol-based epoxy resin is one of the evidences that the wood-derived molecules were chemically incorporated into the network structures. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 745-751, 2011