Synthesis of bio-based poly(ethylene succinate- co -2,5-furandicarboxylate)s copolyester: spinnability, fiber properties and biodegradability

Poly(ethylene furanoate) (PEF) is a bio-based polyester exhibiting remarkable properties, and it is regarded as a sustainable alternative to petroleum-based PET. However, its inherent rigidity leads to poor spinnability and limited biodegradability. Herein, a series of bio-based poly(ethylene succinate-co-2,5-furandicarboxylate) (PESF) copolyesters were prepared synthesized through melt polycondensation. The synthesis employed ethylene glycol (EG), 2,5-furandicarboxylic acid (FDCA), and succinic acid (SA) as monomers, aiming to enhance the spinnability and biodegradability of PEF. The resulting PESFs with varying FDCA/SA molar ratios (ranging from 80/20 to 50/50) were fabricated into fibers via melt spinning. The results presented that increasing the SA content moderately enhanced spinnability and significantly improved flexibility, with elongation at break increasing from 61.75 to 336.23%, though at the cost of reduced tensile strength and modulus. Thermal analysis showed that PESFs retained good thermal stability (T5%>318 °C), despite reductions in melting point, glass transition temperature, and crystallinity at higher SA content. Additionally, enzymatic and hydrolytic degradation confirmed biodegradability, which was accelerated by increased SA incorporation. These results demonstrate that introducing SA effectively balances mechanical properties and environmental degradability, making PESFs promising candidates for sustainable textile fiber applications.