Enzymatically catalyzed furan-based copolyesters containing dilinoleic diol as a building block

An environmentally friendly method for creating sustainable alternatives to traditional aromatic-aliphatic polyesters is a valuable step towards resource-efficiency optimization. A library of furan-based block copolymers was synthesized via temperature-varied two-step polycondensation reaction in diphenyl ether using Candida antarctica lipase B (CAL-B) as biocatalyst where dimethyl 2,5-furandicarboxylate (DMFDCA), α,ω-aliphatic linear diols (α,ω-ALD), and bio-based dilinoleic diol (DLD) were used as the starting materials. Nuclear magnetic spectroscopy (1H and 13C NMR), Fourier transform spectroscopy (FTIR) and gel permeation chromatography (GPC) were used to analyze the resulting copolymers. Additionally, crystallization behavior and thermal properties were studied using X-ray diffraction (XRD), digital holographic microscopy (DHM), and differential scanning microscopy (DSC). Finally, oxygen transmission rates (OTR) of furan-based copolyesters were verified. The results showed that the diol chain length of α,ω-ALD used in the synthesis of poly(alkyl furanoate-co-dilinoleic furanoate) copolymers had a significant effect on the material molecular weight, thermal properties, crystalline structure and oxygen permeability.