Bio-based poly(propylene 2,5-furandicarboxylate-co-propylene 2,5-thiophenedicarboxylate): synthesis and characterization

Poly(propylene 2,5-furandicarboxylate) is a kind of bio-based polyester, but the raw material (2,5-furandicarboxylic acid) is expensive. The purpose of this study is to investigate the effect of cheap 2,5-thiophenedicarboxylic acid on the synthesis and properties of poly(propylene 2,5-furandicarboxylate). 2,5-Furandicarboxylic acid, 2,5-thiophenedicarboxylic acid, and 1,3-propanediol were used to synthesize poly(propylene 2,5-furandicarboxylate), poly(propylene 2,5-thiophenedicarboxylate), and poly(propylene 2,5-furandicarboxylate-co-propylene 2,5-thiophenedicarboxylate). The thermal properties, dynamic mechanical properties, and rheological properties were characterized. The structures and properties of the copolymers were compared with those of two homopolymers. Fourier transform infrared spectroscopy and nuclear magnetic resonance spectra suggested that the copolymers were successfully synthesized. Differential scanning calorimetry and wide-angle X-ray diffraction results showed that poly(propylene 2,5-thiophenedicarboxylate) exhibited better crystallization ability. Compared with poly(propylene 2,5-furandicarboxylate), poly(propylene 2,5-thiophenedicarboxylate) is more prone to βrelaxation due to the larger angle between the two carbonyl groups connected to the thiophene ring and sulfur atom with weaker electronegativity.