Synthesis, Characterization of a Rosin-based Epoxy Monomer and its Comparison with a Petroleum-based Counterpart

A bio-based epoxy derived from dehydroabietylamine was synthesized. In comparison, its petrochemical counterpart based on benzylamine was also prepared. Their chemical structures were confirmed in detail by Fourier Transform Infrared Spectra (FT-IR) and Nuclear Magnetic Resonance (1H-NMR and HSQC). The curing reactions of these synthesized epoxies with hexahydrophthalic anhydride were studied by Differential Scanning Calorimeter (DSC). The mechanical properties and thermal stability of the cured epoxies were investigated by Universal Mechanical Testing Machine, Dynamic Mechanical Analysis (DMA) and Thermogravimetric Analyzer (TGA), respectively. The results indicated that the bulky fused diterpene structure in dehydroabietylamine led to a weaker molecular motion ability and a lower cross-link density, so that the cured epoxy derived from dehydroabietylamine processed a higher glass transition temperature (167°C), but lower mechanical properties than those of the benzylamine-based one.