Cardanol-Based Epoxy Monomers for High Thermal Properties Thermosets

In this paper, epoxy-anhydride networks are synthesized from a new product of Cardolite Corporation: the Cardolite GX-2551 epoxy monomer. Due to the complexity of the GX-2551 structure, an NMR study is performed first to characterize this new commercial product. This epoxy monomer is then reacted with an anhydride (MHHPA) to form polyepoxide thermosets. After curing, dynamic mechanical and thermal analyses are performed for the different thermosets, and then the results are compared to each other. Practical Applications: The cardanol-derived epoxy monomer described in this contribution, i.e., fully epoxidized molecular cardanol, is a new fully biobased monomer for further epoxy thermoset synthesis. The resulting polyepoxide networks exhibit much higher thermo-mechanical properties than previous cardanol-derived epoxy thermosets. Two cardanol-based epoxy monomers are fully characterized. The GX2551 is reported for the first time and exhibits a higher renewable carbon content. Both monomers are reacted with hexahydro-4-methylphtalic anhydride to yield bio-based aromatic polyepoxide networks with interesting mechanical and thermal properties.