LAUSR

Abstract Here an effective solution for overcoming the low glass transition temperature (Tg) of poly(hexamethylene 2,5-furan dicarboxylate) (PHF), a fully biobased polyester derived from dimethylfuran-2,5-furan-dicarboxylate (DMFD) and 1,6-hexanediol (1,6-HD), is proposed that uses isosorbide (Is) as a bicyclic rigid diol comonomer. Incorporating this sugar-derived diol with a broad scope content (3–90 mol%) into PHF macromolecular chain, by melt polycondensation and using titanium (IV) isopropoxide (TTIP) catalyst, results in the synthesis of highly heat-resistive poly(hexamethylene-co-isosorbide-2,5-furandicarboxylates) copolyesters (PHIsF). The chemical structure and composition of the prepared 100% renewable resources-based materials were confirmed in detail by 1H NMR and FTIR spectroscopies. Random microstructures were obtained for PHIsF samples, when Is content exceeds 40 mol%. As revealed by Wide-Angle X-ray Diffraction (WAXD) patterns, increase of IsF content in the copolymers leads to amorphous materials. The latter exhibited an excellent thermal stability up to 360 °C and very variable Tg values oscillating from 10 to 135 °C depending on the comonomer ratio, in which it gradually increases with increasing of Is feed content. Results found herewith showed that the high stiff building block Is can be used as an effective control parameter to spectacularly enhance the thermal properties of polymers, particularly the glass transition temperature. Taking advantage of their features, PHIsF have the potential to serve as promising fully biobased amorphous materials for practical applications that demand high Tg values.