Structure, thermal and mechanical properties of copoly(ester amide)s based on 2,5‐furandicarboxylic acid

In this work, new bio-based copoly(ester amide)s were synthesized by a two-step melt polycondensation process, using 2,5-furanedicarboxylic acid dimethyl ester (DMFDC), 1,3-propanediol (PDO), and 1,3-diaminopropane (DAP), with different DAP content. The chemical structure of the obtained poly(trimethylene 2,5-furandicarboxylate)-co-poly(propylene furanamide) (PTF-co-PPAF) copolymers was confirmed by nuclear magnetic resonance (1H NMR) and Fourier-transform infrared (FTIR) spectroscopy. Gas chromatography/mass spectrometry was used to provide more details of the polycondensation process. Thermal properties of the obtained materials were characterized by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic–mechanical thermal analysis (DMTA). The copolymers were amorphous and their glass transition temperature increased with the increase in the poly(propylene furanamide) (PPAF) content. The synthesized PTF-co-PPAF copolymers exhibited improved thermal and thermo-oxidative stability up to 300 °C. In addition, from the performed mechanical tests, it was found that along with the increase in PPAF content, Young's modulus increased, while at the same time, the value of elongation at break decreased.