Bio-based Poly(butylene 2,5-furandicarboxylate-co-glutarate): The Effect of Glutaric Acid on the Properties of Poly(butylene 2,5-furandicarboxylate)

Bio-based poly(butylene 2,5-furandicarboxylate) (PBF) has high tensile strength, but low elongation at break. To improve the toughness, this study employed 1,5-glutaric acid (GA) to synthesize poly(butylene 2,5-furandicarboxylate-co-glutarate) (PBFG). The impact of GA on PBF’s composition and properties was investigated in detail. The thermal decomposition temperature exceeded 350 °C, and as the concentration of GA rose, the thermal decomposition behavior gradually grew closer to poly(butylene glutarate) (PBG). In accordance with DMA, GA enables PBF’s glass transition temperature to fall from 44.4 °C to -52.7 °C. The copolyester’s toughness is substantially improved by adding a portion of GA. PBFG25 with high tensile strength of 61.5 MPa and high elongation at break of 856% combines exceptional toughness and high tensile strength. After the tensile test, the transparency of PBFG25 and PBFG50 increased, the melting enthalpy of DSC decreased, and they rebounded after the fracture. The above results support the mesophase hypothesis of furan-based polyesters. This paper presents the theoretical foundations for the controlled structure and property enhancement of bio-based polyesters.