Biobased high-performance polyesters: Synthesis and thermal properties of poly(isoidide furanoate) and co-polyesters

[Display omitted] •Fully biobased polyesters based on isoidide were synthesized and characterized.•The molecular weight of the polyesters was enhanced by SSPC.•Adding small amounts of aliphatic diol as comonomer did not inhibit crystallization.•Poly(isoidide furanoates) are a promising class of high-performance polyesters. A fully biobased high-performance polyester was prepared by the sequential melt polymerization and solid-state post-condensation of the symmetrical 1,4:3,6-dianhydrohexitol isoidide and dimethyl 2,5-furandicarboxylate (FDME). The thermal properties of the resulting poly(isoidide furanoate) were well within the “high-performance” range with a glass transition- and melting temperature of approx. 165 and 280 °C, respectively. Since such a high melting temperature does not allow for conventional melt processing without thermal degradation of the polymer, various C2-C4 diol comonomers were incorporated in an attempt to create semi-crystalline co-polyesters with a high-glass-transition-temperature and sufficiently low melting point. It was found that semi-crystalline co-polyesters could be obtained with either low (3–5 mol%) or high (80–95 mol%) isoidide contents. All semi-crystalline co-polyesters with low diol comonomer contents (≤20 mol%) had still glass transition temperatures ≥ 118 °C despite having low molecular weights. Co-polyesters with a high diol comonomer content had lower melting points than the PiIF homopolymer, as well as a significantly lower glass transition temperature. The molecular weight of the PiIF homopolymer and a semicrystalline poly(ethylene-co-isoidide furanoate) co-polyester could be significantly enhanced by solid-state post-condensation. Thus, poly(isoidide furanoates) are an interesting class of new fully biobased polyesters that has potential in high-performance applications.