Modification of Poly(ethylene 2,5-furandicarboxylate) with Bio-based 1,5-Pentanediol: Significantly Toughened Copolyesters Retaining High Tensile Strength and O2 Barrier Property.
writer：Hongzhou Xie, Linbo Wu*, Bo-Geng Li, Philippe Dubois*.
keywords：Biobased polymers, polyesters, high performance, gas barrier, polymer toughening, mechanical properties
source：期刊
specific source：Biomacromolecules 2019, 20, 353?364 DOI: 10.1021/acs.biomac.8b01495
Issue time：2019年
Poly(ethylene 2,5-furandicarboxylate) (PEF) is a biobased polyester characterized by high gas barrier properties as well as high tensile modulus and strength, but poor toughness. Toughening PEF without sacrificing its modulus, strength and gas barrier performance is a great challenge for PEF modification. In this study, high molecular weight random poly(ethylene-co-1,5-pentylene 2,5- furandicarboxylate)s (PEPeFs) were synthesized via melt
copolycondensation of 2,5-furandicarboxylic acid (FDCA), ethylene glycol (EG) and 1,5-pentanediol (PeDO), a cheap, biobased and commercially available odd-carbon comonomer. The synthesized PEPeFs were characterized and assessed with intrinsic viscosity, ATR-FTIR, 1H NMR, DSC, TGA and tensile, impact and O2 permeation test. Mayo?Lewis equation with
“reactivity ratio” of 3.78 for PeDO and 0.75 for EG could be used as an empirical equation to correlate the copolyester composition (?PeF) with monomer composition. PEPeFs proved nearly amorphous copolyesters having excellent thermal stability. Brittle?ductile transition was achieved at ?PeF as low as 9 mol %. Increasing ?PeF led to increase in elongation at break
and notch impact strength and decrease in Tg, O2 barrier performance and tensile modulus and strength. However, in comparison with PEF, PEF-rich PEPeFs (?PeF 9?47%) not only showed greatly improved elongation at break (29?265% vs 4%) and enhanced impact strength (2.2?3.9 kJ/m2) but also retained very high Young’s modulus (2.8?3.3 vs 3.3 GPa) and yielding strength (72?83 vs 82 MPa). Particularly, when compared with bottle-grade PET, PE82Pe18F possesses equal Tg (ca. 75 °C) and comparable elongation at break (ca. 115%), but greatly improved yielding strength (83 MPa) and O2 gas barrier property (4.8 times). As modified PEF materials possessing superior thermo-mechanical and O2 gas barrier properties, these integrally biobased copolyesters may find practical applications in eco-packaging and other fields.