Synthesis of novel bio-based amines from vanillin and guaiacol for high performance epoxy thermosets

Abstract

In this work, a novel bio-based diamine was successfully synthesized from lignin-derived vanillin. This marks the first report of the synthesis and characterization of 1,3-bis(aminomethyl)-4,5-dimethoxybenzol (Dimethoxy-MXDA). Furthermore, 2,4-bis(dimethylaminomethyl)-6-methoxyphenol (Methoxy-K54) has been successfully synthesized in one step from bio-based guaiacol, another major lignin derivative. Dimethoxy-MXDA was used as a bio-based amine hardener in the synthesis of an epoxy thermoset polymer and showed similar to superior performance when compared to a petrol-based reference system containing the industrially common m-xylylenediamine (MXDA) hardener. In particular, the post-cured samples of the bio-based system outperformed the petrol-based benchmark material in all properties. Furthermore, the bio-based hardener Methoxy-K54 showed comparable properties to the petrol-based analogue 2,4,6-tris(dimethylaminomethyl)phenol (Ancamine® K54).