Synthesis, Characterization, and Biodegradability of Novel Fully Biobased Poly(decamethylene-co-isosorbide 2,5-furandicarboxylate) Copolyesters with Enhanced Mechanical Properties

This study spotlighted a successful synthesis of a novel series of biobased poly­(decamethylene-co-isosorbide 2,5-furandicarboxylate)­s (PDIsFs) copolyesters from dimethylfuran-2,5-dicarboxylate (DMFD), isosorbide (Is), and 1,10-decanediol (1,10-DD) by melt polycondensation, using titanium­(IV) isopropoxide (TTIP). The chemical structure and composition of prepared polymers were confirmed in detail by 1H NMR and FTIR spectroscopies. Satisfactory weight-average molecular weights (M w) in the 55,300–84,500 g/mol range and random microstructures were obtained for PDIsFs. It was shown that Is unit incorporation into the copolyesters molecular chains was dramatically effective in increasing the glass transition temperatures (T g) and in delaying the onset decomposition temperatures of PDIsFs. Hence, an excellent improvement of the thermal stability exceeding 405 °C for all copolymers was obtained. In addition, the degradation behavior in soil as well as the mechanical properties of PDIsFs were duly investigated in detail. The biodegradation rate of the copolyesters depended on the comonomer ratio. Rotational rheometry characterization of polymer melts revealed prevailing viscous properties for all formulations, whereas the presence of isosorbide favored a Newtonian behavior. Oxygen induction time (OIT) measurements by chemiluminescence (CL) demonstrated that isosorbide incorporation also dramatically increases polymer thermo-oxidative stability. Taking advantage of their features, PDIsFs have the potential to serve as promising and innovative biobased polymers for practical applications such as ecofriendly and sustainable plastic packaging.