Sustainable paeonol-derived polyimine-epoxy as a substitute for DGEBA thermoset

The bisphenol A epoxy resin is primarily reliant on petrochemicals and shows biological toxicity. To overcome such a disadvantage, both academia and industry attempt to explore both bio-based monomers and their functional polymers. A stable epoxy monomer with a proper melting point promotes a solvent-free, environmentally friendly curing technique. To address related problems, a novel bio-based mono-aromatic epoxy resin, 1-(2,4-bis(oxiran-2-ylmethoxy)phenyl)-ethan-1-one (BPEO) was derived from paeonol herein. Such a BPEO monomer allowed the mild fabrication of novel polyimine-epoxy resins with apparent activation energies ranging from 46.9 to 54.1 KJ/mol. The resultant polyimine-epoxy resins showed increased dynamic mechanical properties and adhesion values as well as relatively high char residue up to 37.3 wt%. In addition, analogous to the diglycidyl ether of bisphenol-A (DGEBA) counterpart, BPEO-derived epoxy resins behaved with comparable mechanical and thermal stability properties. Similar chemical and solvent resistance were also revealed for the biobased BPEO networks when compared to the DGEBA counterparts. Notably, the inherent NTE behaviors for these epoxy resins were also first presented which varied from −71.1 to −430.9 ppm/^oC. In addition, through the bio-based or petroleum-based resorcinol transformation, the BPEO can be readily scaled up, and those will deliver excellent development for its industrial applications.