Synthesis of amide-functionalized furan-based polyesters via a combined ring-opening polymerization and melt polycondensation strategy

Abstract

Aliphatic polyesters exhibited excellent biodegradability and biocompatibility, which have been utilized in various fields. However, their practical implementation in high-performance applications, particularly those requiring elevated temperature processing, remains constrained by inherent limitations in thermal stability, which compromises structural integrity during process and accelerates hydrolytic degradation under operational stresses. In this work, a series of high-performance polyesters with significantly improved thermal stability were prepared by strategic incorporation of amide bonds and furan moieties within the polymer backbone. The 1,5-pentanediamine (PDA) initiated ring-opening polymerization (ROP) of cyclic monomers was systematically explored, enabling the synthesis of amide-functionalized aliphatic polyester diols with controlled molecular weights (1.10–15.55 kg/mol), including poly(ε-caprolactone), poly(δ-valerolactone) and poly(l-lactide). These polymers exhibited narrow dispersities (Ð_M = 1.08–1.20) and high amide fidelity (up to 98 %). Kinetic studies indicated the well-controlled feature of PDA initiated ROP. Subsequently, melting polycondensation of PCL diol and dimethyl 2,5-furandicarboxylate (DMFDCA) was conducted to obtain furan-amide modified PCL (PCLF). The thermal decomposition temperature (T_d,0.5 %) of the obtained PCLF showed a 54 °C enhancement relative to PCL diol. These results demonstrate that the introduction of amide groups and furan rings constitutes a powerful approach to enhance the thermal stability of various polymers.