Synthesis of an aromatic amine derived from biomass and its use as a feedstock for versatile epoxy thermoset

Abstract

Innovative bio-based monomers and polymers are required as substitutes for limited fossil resources. Aromatic amines as an important class of chemicals are currently mostly formulated from petroleum. In this paper, a guaiacol derivative aromatic amine (5-aminoguaiacol) was designed and successfully synthesized, which was employed together with vanillin to build a high bio-based bisphenol compound. Following by glycidylation and cross-linking with 4,4′-diaminodiphenyl methane (DDM), we presented an epoxy resin network (GV-EP/DDM) bearing dynamic Schiff base bonds with high glass transition temperature of 220 °C, char yield (in N2 at 800 °C) of 44.9%, storage modulus at 30 °C of 3602 MPa, and Young's modulus of 4489 MPa, which was 33 °C, 2.5-fold, 38% and 28% higher than those of bisphenol A epoxy resin, respectively. Furthermore, the introduction of Schiff base structure endowed the GV-EP/DDM system with shape memory, degradability, reprocessability at 230 °C under 10 MPa, as well as satisfactory antibacterial property. Notably, the higher crosslinking density made GV-EP/DDM have stronger acid resistance than the other epoxy resins with Schiff base bonds. This work provides a feasible toolbox for production of bio-based aromatic amine compounds, and a strategy to construct high performance and versatile bio-based polymer materials.