Influence of the 2,5-Furandicarboxamide Moiety on Hydrogen Bonding in Aliphatic–Aromatic Poly(ester amide)s

Abstract

We address the synthesis of novel poly(ester amide)s containing 2,5-furandicarboxylic acid (2,5-FDCA). A dimethyl 4,4′-((furan-2,5-dicarbonyl)bis(azanediyl))dibenzoate (2,5-FDCAn) model compound is synthesized to protect the thermally instable carboxylic acid groups of the 2,5-FDCA moiety. The properties of 2,5-FDCAn are compared with its terephthalic acid (TA), 2,5-thiophenedicarboxylic acid (2,5-TDCA), and isophthalic acid (IA) analogues. Furthermore, the feasibility of the melt polycondensation reaction of these model compounds with different aliphatic diols is investigated. The polymers thus synthesized are analyzed using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), polarization optical microscopy (POM), nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and wide-angle X-ray diffraction (WAXD). Solution NMR analysis indicates that the oxygen heteroatom in the furan ring functions as a hydrogen bond acceptor, resulting in the for...