From 2,5-furandicarboxylic Acid Research Articles

Modifications of Furan-Based Polyesters with the Use of Rigid Diols.

The replacement of polymers derived from petrochemical resources has been a prominent area of focus in recent decades. Polymers used in engineering materials must exhibit mechanical strength and stiffness while maintaining performance through a broad temperature range. Most of the polyesters used as engineering materials are based on terephthalic acid (TPA) and its derivatives, which provide necessary rigidity to molecular chains due to an aromatic ring. Bio-based alternatives for TPA-based polyesters that are gaining popularity are the polyesters derived from 2,5-furandicarboxylic acid (FDCA). To broaden applicational possibilities, one effective way to achieve specific properties in targeted applications is to adjust the composition and structure of polymers using advanced polymer chemistry techniques. The incorporation of rigid diols such as isosorbide, 1,4-cyclohexanedimethanol (CHDM), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO) should result in a greater stiffness of the molecular chains. This review extensively explores the effect of incorporating rigid diols on material properties through a review of research articles as well as patents. Moreover, this review mainly focuses on the polyesters and copolyesters synthesized via two-step melt polycondensation and its alterations due to the industrial importance of this method. Innovative synthesis strategies and the resulting material properties are presented.

Highly selective oxidation of 5-HMF to HMFCA via a facile Pt-Ag co-catalytic strategy

5-Hydroxymethyl-2-furancarboxylic acid (HMFCA) is an important feedstock in chemical and pharmaceutical industries. Its production through aerobic conversion of 5-hydroxymethylfurfural (5-HMF) has promising prospects but is challenged by the over-oxidation. In this work, we develop a refined Pt-Ag co-catalytic strategy to tailor the selectivity of 5-HMF’s aerobic oxidation. By simple in situ addition of AgNO3 to the thermal catalytic system of Pt nanoparticles, the main products of 5-HMF oxidation could be shifted from 2,5-furandicarboxylic acid (FDCA) to HMFCA with an ultrahigh selectivity of over 99%. Density functional theory calculations demonstrate that such strategy could alter the HMFCA adsorption sites from Pt to Ag sites and prevent the oxidation of hydroxymethyl group. In addition, this strategy can be extended to other Ag species, such as AgCl, Ag2O and AgO. This work provides insights into the Pt-Ag synergistic catalysis and opens up a simple avenue to control the product selectivity for biomass refinement.

Poly(ether‐ester)s synthesized from furandicarboxylic acid and ethylene glycol using an acidic binary catalyst

AbstractPoly(ethylene 2,5‐furandicarboxylate) (PEF) is an important biobased polyester with better thermal, mechanical, and gas barrier properties than poly(ethylene terephthalate). In PEF synthesis, diethylene glycol furandicarboxylate (DF) is inevitably formed via etherification side reaction. Taking advantage of the side reaction, poly(ethylene‐co‐diethylene furandicarboxylate) (PEDF) poly(ether‐ester)s were synthesized only from 2,5‐furandicarboxylic acid (FDCA) and ethylene glycol (EG), using a cheap binary propanedisulfonic acid/dibutyltin oxide (PSA/DBTO) catalyst. The polymers were characterized by 1H NMR, intrinsic viscosity, solubility, differential scanning calorimetry, thermogravimetric analysis, tensile, and gas barrier test. Due to strong acidity of PSA, not only major DF but also minor oligoethylene glycol furandicarboxylate ether‐containing units were formed. Their total content can be adjusted up to 78 mol% by simply increasing the dosage of PSA from 0 to 0.4 wt%. The effect of ether‐containing units on the solubility, thermal transition, mechanical, and oxygen barrier properties of the poly(ether‐ester)s were examined and compared with the poly(ether‐ester)s synthesized via copolycondensation.

High toughness, UV & blue light shielding and antibacterial bio-based PEF/TiO2 nanowires composites for packaging application

As a candidate of fossil-based poly(ethylene terephthalate) (PET), bio-based poly(ethylene 2,5-furandicarboxylate) (PEF) that could be converted from renewable resources has attracted attention from academia and industry. Here, we prepare a series of new type of PEF/TiO2 NWs composites from 2,5-furandicarboxylic acid (FDCA), ethylene glycol (EG), titanium dioxide nanowire (TiO2 NWs, diameter∼100 nm, length∼20 µm) and dipentaerythritol (Di-PE) via in-situ polymerization. The TiO2 nanowires (0.5∼10 wt‰ based on PEF) and Di-PE (3 mol‰ based on FDCA) were added as fillers and extenders. TiO2 nanowires were distributed in the PEF uniformly, shown by SEM. Compared with pure PEF, the Tg and thermal stability of all nanocomposites got improved. And the impact strength of nanocomposites could reach 60 kJ/m2 in contrast to brittle pure PEF. The UV-A and blue-light shielding of nanocomposites increased from 53 % to 98 % and 28 % to 86 %, respectively, and the nanocomposites still maintained good gas barrier properties. Moreover, the antibacterial activity of nanocomposites against E. coli had increased to 98 %, better than that of the PEF/Ag NWs composites. By uniaxial pre-stretching, the tensile modulus and the elongation at break were improved obviously, from 1840 MPa to 5466 MPa and 4 % to 54 % respectively with pre-stretching ratio increasing. Compared to the PET/TiO2 NWs composites, the PEF/TiO2 NWs composites shows batter thermal property and mechanical property. The PEF/TiO2 NWs composites exhibit potential foreground in the packaging application.

Synthesis of bio-based poly(ester-ether) elastomers from 2,5-furandicarboxylic acid (FDCA) with excellent thermo-mechanical properties

As a novel polyester possessing high melting temperature and well crystallization ability, poly(1,4-cyclohexanedimethylene furandicarboxylate) (PCF), produced from bio-based 2,5-furandicarboxylic acid and 1, 4-cyclohexanedimethanol, could be used as promising hard segment to develop new bio-based thermoplastic poly(ether-ester) elastomer (TPEE). Multiblock poly(ether-ester)s based on PCF, with molecular weight (Mn) of soft segments poly(tetramethylene glycol) (PTMG) ranging from 250 to 2900 g/mol while maintaining the weight fraction at 70%, were synthesized to investigate the effects of soft segments length on microphase structure and thermodynamic properties of copolymers. The results show that the increase in Mn of the soft segment promotes the microphase separation of the copolymers. Macroscopically, copolymers have excellent comprehensive properties. Tm was promoted from 126.0 to 228.7 °C, and Td,5% was higher than 320 °C. The tensile strength and modulus of resulting copolymers were within the range of 14–26 MPa and 29–53 MPa, respectively, with elongation at break exceeding 550%. The copolymer exhibited elastic recovery ratio of 75.5% at 200% strain when the Mn of PTMG unit was 2000 g/mol. This work introduces a new bio-based TPEE and enriches a detailed understanding of the impact of soft segments length on the structural properties of TPEE, which is fundamental to design tailor-made TPEE with desired properties.

Bio-based poly(decylene terephthalate-co-decylene furandicarboxylate)s derived from 2,5-furandicarboxylic acid (FDCA): Synthesis and properties

Currently, a growing focus is devoted to the creation and utilization of renewable resources for bio-based polyesters due to the shortage of oil resources. Since 2,5-furandicarboxylic acid (FDCA) has been described as one of the most promising platform compounds, FDCA-based polyesters have been rapidly developed. Poly(decylene terephthalate-co-decylene furandicarboxylate) (PDTFs) in this study were prepared from dimethyl terephthalate (DMT), 1,10-decanediol (DDO) and dimethyl 2,5-furandicarboxylate (DMFD). By using 1H NMR and 13C NMR, the polyesters' chemical structure was verified. The thermal properties and the thermal stability of the polyesters were analyzed by Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TGA). All polyesters underwent mechanical testing to ascertain their Young's modulus, tensile strength, and elongation at break. All polymers are semi-crystalline materials. The crystal texture of PDTF24 is equivalent to that of poly(decylene terephthalate) (PDT). However, the crystal structures of PDTF48 and PDTF76 are similar to that of poly(decylene furandicarboxylate) (PDF). All polymers exhibit high thermal stability. PDF has the highest tensile strength, probably because the oxygen atom on the furan ring results in stronger intermolecular interactions. When the content of the decylene furandicarboxylate unit reaches 48%, Young's modulus reaches its lowest value (96.6 MPa), but its elongation at break reaches its highest value (1098%) due to the lowest crystallinity.

Efficient Production of Adipic Acid by a Two-Step Catalytic Reaction of Biomass-Derived 2,5-Furandicarboxylic Acid.

Efficient catalytic ring‐opening coupled with hydrogenation is a promising but challenging reaction for producing adipic acid (AA) from 2,5‐furan dicarboxylic acid (FDCA). In this study, AA synthesis is carried out in two steps from FDCA via tetrahydrofuran‐2,5‐dicarboxylic acid (THFDCA) over a recyclable Ru/Al2O3 and an ionic liquid, [MIM(CH2)4SO3H]I (MIM=methylimidazolium) to deliver 99 % overall yield of AA. Ru/Al2O3 is found to be an efficient catalyst for hydrogenation and hydrogenolysis of FDCA to deliver THFDCA and 2‐hydroxyadipic acid (HAA), respectively, where ruthenium is more economically viable than well‐known palladium or rhodium hydrogenation catalysts. H2 chemisorption shows that the alumina phase strongly affects the interaction between Ru nanoparticles (NPs) and supports, resulting in materials with high dispersion and small size of Ru NPs, which in turn are responsible for the high conversion of FDCA. An ionic liquid system, [MIM(CH2)4SO3H]I is applied to the hydrogenolysis of THFDCA for AA production. The [MIM(CH2)4SO3H]I exhibits superior activity, enables simple product isolation with high purity, and reduces the severe corrosion problems caused by the conventional hydroiodic acid catalytic system.

Synthesis of bio‐based polyesters with crystallization properties comparable to poly(butylene terephthalate)

AbstractTo enhance the crystallization of poly(butylene 2,5‐furandicarboxylate) (PBF) thus substitute its petroleum‐based analogue poly(butylene terephthalate) (PBT), a series of high molecular weight poly(butylene‐co‐1,4‐cyclohexanedimethylene 2,5‐furandicarboxylate) (PBCF) copolyesters with low contents (0–19 mol%) of 1,4‐butanediol (BDO) are synthesized from 2,5‐furandicarboxylic acid (FDCA), 1,4‐cyclohexanedimethylene (CHDM) and BDO. Their chemical structures and compositions are confirmed by nuclear magnetic resonance (1H NMR and 13C NMR). Their number average molecular weights are from 20,500 to 36,100 g/mol with the polydispersity index (Ð) of 1.67–1.99. The thermal stability and crystallization behaviors are investigated by thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC). Results show that PBCFs demonstrate comparable crystallization rate to PBT as the crystallization half time is from 18 to 29 s and the melting enthalpy is 34.1–41.4 J/g as well as the higher melting temperature of 238–263°C than 225°C for PBT. In addition, PBCFs exhibit excellent mechanical properties of tensile modulus between 1220 and 1510 MPa. These investigations suggest that a moderate amount CF unit can improve the melting temperature and enhance the originally weak crystallizability of furan‐based polyesters. Generally, PBCFs can be the engineering plastic with satisfied thermal and mechanical performance.

Gas barrier properties of furan-based polyester films analyzed experimentally and by molecular simulations

“Green” alternatives for petroleum-derived engineering plastics, like poly(ethylene terephthalate) (PET), include polyesters synthesized from 2,5-furan-dicarboxylic acid (FDCA). FDCA-based polyesters attracted a lot of attention from scientists and engineers because of their excellent gas barrier properties. This work analyzed, theoretically and experimentally, the transport properties of oxygen and carbon dioxide in amorphous poly(ethylene 2,5-furandicarboxylate) (PEF), poly(propylene 2,5-furandicarboxylate) (PPF) and poly(butylene 2,5-furandicarboxylate) (PBF) films. Molecular simulations studied the effect of the furan-based polyesters containing different amounts of methylene on the films' gas transport performance and other properties. The adsorption capacity and active sites in the films were assessed using the Grand Canonical Monte Carlo (GCMC) method. The gas molecule diffusion through the films was analyzed by the molecular dynamics approach. The permeability of three polymers are extremely low. Specifically, PEF and PPF showed almost no difference in their gas permeability. However, as the methylene groups amount increased to 4 (in PBF), the oxygen permeability increased significantly while barely any changes in CO2 were observed. We also prepared furan-based polyester films to experimentally assess their permeation performance, which agreed with the results obtained by simulations. This work provided some insights into the permeability and formation mechanisms of these films. In particular, the non-linear axis of ring rotation coupled with the dipolarity of the heterocycle in furan-base polyesters significantly hinders its furan ring-flipping. This feature is favorable in advancing furan-based polyesters as novel materials for food packaging applications.

Synthesis and Characterization of Bio-Based Polymer Derived from 2,5-Furandicarboxylic Acid and 1,4- Butanediol

Nowadays, petroleum-based polymers are currently dominant in material industries, with wide scope applications. However, due to the finite supply of fossil fuels as well as the negative effects on the environment while utilizing them, the need of developing bio-based alternatives is dramatically increase. Recently, the biopolymers derived from 2,5-furandicarboxylic acid (FDCA) have been gradually investigated; however, some of their thermal and mechanical properties are not fully understood. Herein, we are conducting research about a FDCA-derived biopolymer – poly(butylene 2,5-furandicarboxylate) (PBF), which was synthesized from FDCA and butane-1,4-diol by the melting polycondensation.1H NMR and IR spectrum confirmed the linear structure of this polyester, then TGA and DSC results were analyzed to indicate the melting point at 159 ºC and the thermal degradation at 357 ºC.

Preparation of biobased poly(propylene 2,5‐furandicarboxylate) fibers: Mechanical, thermal and hydrolytic degradation properties

AbstractIn this work, a fully biobased poly(propylene 2,5‐furandicarboxylate) (PPF) was synthesized from 2,5‐furan dicarboxylic acid (FDCA) and 1,3‐propanediol (1,3‐PDO) via traditional two‐step melting polycondensation. Then, the resultant PPF was characterized with 1H NMR, FTIR, GPC, intrinsic viscosity, TGA, and DSC measurements, respectively. Next, the prepared PPF was melt‐spun into fibers. The morphology and thermal stability of the as‐spun PPF fibers were firstly investigated by SEM and TGA. Furthermore, the mechanical properties of the PPF fibers were evaluated. The results showed that the tensile of the PPF fibers increased with increasing of the draw ratios following gradual decrease of the breaking elongation from 307.1% to 48.9%. In addition, the crystallization ability and the hydrolytic degradation behavior of the as‐spun PPF fibers were investigated in detail as well. The results presented that comparing to traditional fossil‐based poly(trimethylene terephthalate) (PTT) fibers, the PPF fibers exhibited lower crystallinity, however, it displayed a better hydrolytic degradation performance. Based on these results, it confirmed that the PPF fiber based on biomass polymer is a kind of promising environmentally friendly synthetic fiber for potential application in various fields.

Bio-based copolyesters poly(butylene 2,6-naphthalate-co-butylene furandicarboxylate) derived from 2,5-furandicarboxylic acid (FDCA): Synthesis, characterization, and properties

A series of copolymers poly(butylene 2,6-naphthalate-co-butylene furandicarboxylate) (PBNFs) derived from 2,5-furandicarboxylic acid (FDCA) were synthesized. The molecular weight, microstructures, thermal and mechanical properties were characterized. DSC results show that PBN and PBNF25 can crystallize rapidly. However, the crystallization rates of PBNF50, PBNF75 and PBF are very slow. The Td,5% and Td,max values of all polyesters were higher than 360 °C and 390 °C, respectively. Compared with PBN, PBNF25, PBNF50, PBNF75 and PBF exhibited much higher elongation at break (214–295%) and bio-based content (46–100%).

Fully Bio-based Micro-cellulose Incorporated Poly(butylene 2,5-furandicarboxylate) Transparent Composites: Preparation and Characterization

Poly(butylene 2,5-furandicarboxylate) (PBF) derived from 2,5-furandicarboxylic acid (FDCA) is an emerging bio-based alipharomatic polyester that is expected to replace its fossil-based terephthalate and naphthate homologues. PBF holds excellent gas barrier properties, but its slow rate of crystallization might restrict wider applications. To improve the rate of crystalization, it was melt-blended with crystalline micro-cellulose (CMC) to prepare a composite through twin-screw extrusion. To ensure environmental friendly conditions, neither chemicals to modify fibers nor compatibilizers to improve the filler/matrix interaction were used. Size exclusion chromatography (SEC), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and X-ray diffraction (XRD) were used to characterize the composite. It was observed that a longer blending duration (cyclic mode) leads to a greater reduction in molecular weight (Mw) in the presence of CMC, which can be avoided by using a shorter blending duration (direct mode). The mechanical properties of the composite showed an increase in Young’s modulus by approximately 23 % and 36 % with respect to reference PBF for the cyclic and direct mode respectively. It was further observed that, although the elongation at break and tensile strength has decreased, it has improved gas barrier properties. Thermal analysis shows faster nucleation of PBF in the presence of CMC with a minor effect on its thermal degradation.

Biobased Poly(ethylene-co-hexamethylene 2,5-furandicarboxylate) (PEHF) Copolyesters with Superior Tensile Properties

Poly(ethylene-co-hexamethylene 2,5-furandicarboxylate) (PEHF) copolyesters with high intrinsic viscosity were synthesized from 2,5-furandicarboxylic acid (FDCA), ethylene glycol (EG), and 1.6-hexanediol (HDO) through two-step melting polycondensation, characterized with 1H NMR, DSC, WAXD, and TGA, and assessed by tensile and impact tests. The molar fraction of HF unit in PEHF (ϕHF), namely, copolymer composition, is higher than the molar fraction of HDO in the feeding diols and can be predicted empirically via Mayer–Lewis equation with apparent reactivity ratio rHDO = 4.6 and rEG = 0.74. All the PEHFs exhibited a single glass transition temperature and excellent thermal stability. HF-rich (ϕHF ≥ 88 mol %) PEHFs are semicrystalline but the others are almost amorphous. In comparison with PEF, PEHFs with ϕHF of 28–36 mol % possess significantly improved tensile ductility (elongation at break 54–160%) and retain high tensile modulus (2.6–2.2 GPa) and yielding strength (71–65 MPa). The tensile properties are comparable to those of bottle-grade PET.

Furanoate-Based Nanocomposites: A Case Study Using Poly(Butylene 2,5-Furanoate) and Poly(Butylene 2,5-Furanoate)-co-(Butylene Diglycolate) and Bacterial Cellulose.

Polyesters made from 2,5-furandicarboxylic acid (FDCA) have been in the spotlight due to their renewable origins, together with the promising thermal, mechanical, and/or barrier properties. Following the same trend, (nano)composite materials based on FDCA could also generate similar interest, especially because novel materials with enhanced or refined properties could be obtained. This paper presents a case study on the use of furanoate-based polyesters and bacterial cellulose to prepare nanocomposites, namely acetylated bacterial cellulose/poly(butylene 2,5-furandicarboxylate) and acetylated bacterial cellulose/poly(butylene 2,5-furandicarboxylate)-co-(butylene diglycolate)s. The balance between flexibility, prompted by the furanoate-diglycolate polymeric matrix; and the high strength prompted by the bacterial cellulose fibres, enabled the preparation of a wide range of new nanocomposite materials. The new nanocomposites had a glass transition between −25–46 °C and a melting temperature of 61–174 °C; and they were thermally stable up to 239–324 °C. Furthermore, these materials were highly reinforced materials with an enhanced Young’s modulus (up to 1239 MPa) compared to their neat copolyester counterparts. This was associated with both the reinforcing action of the cellulose fibres and the degree of crystallinity of the nanocomposites. In terms of elongation at break, the nanocomposites prepared from copolyesters with higher amounts of diglycolate moieties displayed higher elongations due to the soft nature of these segments.

Synthesis and structure – property relationship of biobased poly(butylene 2,5-furanoate) – block – (dimerized fatty acid) copolymers

A series of poly(butylene 2,5-furanoate) – block – (dimerized fatty acid) (PBF-b-FAD) copolymers were successfully synthesized from 2,5-furandicarboxylic acid (FDCA), 1,4-butanediol (1,4-BD), and dimerized fatty acid diol (FADD) via a polycondensation in melt under the relatively mild process conditions and a reasonable excess of diol. The copolymers with different PBF to FAD segment ratio were characterized in regard of their chemical composition, microstructure, thermal transitions and stability as well as the mechanical performance. Some results were also discussed in relation to terephthalic acid based PBT-b-FAD copolymers, synthesized under the same experimental procedure. A detailed analysis of PBF homopolymer confirmed its relatively high molecular weight, semicrystalline structure, and in consequence a very good mechanical performance. In turn an incorporation of FADD amorphous segments between PBF blocks resulted in multiblocked structure with the ester group links and the real composition very close to those calculated theoretically. Although the specific furan ring architecture disturbs the macromolecules symmetry, thus the crystallization process, the PBF-b-FAD copolymers, varying in between 20 and 80 wt% of the rigid segments, reveal the heterogeneous microstructure. And the phase separation may be enhanced by the annealing above Tcc. In consequence the furan-aromatic copolyesters combine a variety of physical properties (also the elastomeric behavior), tunable by both PBF to FAD ratio and the thermal treatment, with a good processability. They are also characterized by almost twice higher level of the tensile stress and E modulus when compared to previously reported PTF-b-FADD copolymers. Considering the soon commercialization of bio-1,4-butanodiol the presented materials have also a potential to be synthesized as fully bio-based.

Copolyesters Based on 2,5-Furandicarboxylic Acid (FDCA): Effect of 2,2,4,4-Tetramethyl-1,3-Cyclobutanediol Units on Their Properties.

Bio-based polyesters derived from 2,5-furandicarboxylic acid (FDCA), including poly (ethylene 2,5-furandicarboxylate) (PEF), poly(propylene 2,5-furandicarboxylate) (PPF), and poly(butylene 2,5-furandicarboxylate) (PBF) have been synthesized and modified with 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO). Copolyesters with increased glass transition temperature, good barrier and better mechanical properties, as well as higher transparency were reported in this work. The chemical structures, composition, and sequence distribution of the copolyesters were determined by 1H NMR and 13C NMR. The degree of random (R) was close to 1 for all the copolyesters, indicating their random chemical structures. With the introduction of 10% CBDO units, the semi-crystalline PEF and PPF were changed into completely amorphous polyesters and the higher transparency was easily achieved. The glass transition temperature was increased from 87 °C for PEF to 91.1 °C for PETF-18, from 55.5 °C for PPF to 63.5 °C for PPTF-18, and from 39.0 °C for PBF to 43.5 °C for PBTF-18. The barrier properties investigation demonstrated that although the O2 and CO2 barrier of PEF/PPF/PBF were decreased by the addition of CBDO units, the modified copolyesters still showed good barrier properties.

Biobased copolyesters: Synthesis, sequence distribution, crystal structure, thermal and mechanical properties of poly(butylene sebacate-co-butylene furandicarboxylate)

Fully biobased poly(butylene sebacate-co-butylene furandicarboxylate) (PBSFs) copolyesters were synthesized using a two-step melt polycondensation method from 2,5-furandicarboxylic acid (FDCA), sebacic acid(SA), and 1,4-butanediol (BDO). The composition, molecular weight, crystal structure, and thermal properties of PBSFs were investigated by 1H NMR, GPC, WAXD, DSC and TGA, respectively. Tensile properties were also evaluated. The number average molecular weight (Mn) ranges from 35600 to 46200 g/mol. PBSFs are all random copolyesters and exhibit excellent thermal stability. The glass transition temperature (Tg) and melting point temperature (Tm) of PBSFs gradually decreased with the increasing of butylene sebacate (BS) unit content (ФBS). Compared with poly(butylene furandicarboxylate) (PBF), PBSFs exhibit lower Tg and crystallinity. Thus, the ductility of PBF is substantially improved (the elongation at break (εb) of PBSFs ranges from 100 to 780%).

Modification of poly(ethylene 2,5-furandicarboxylate) with 1,4-cyclohexanedimethylene: Influence of composition on mechanical and barrier properties

A series of poly(ethylene-co-1,4-cyclohexanedimethylene 2,5-furandicarboxylate)s (PECFs) with different compositions were synthesized from 2,5-Furandicarboxylic acid (FDCA), 1,4-cyclohexanedimethylene (CHDM) and ethylene glycol (EG). Their chemical structures, composition and sequence distribution were determined by FT-IR, 1H NMR and 13C NMR. The composition of the resulted polyesters could be controlled by the feed mole ratio of CHDM to dimethyl furan-2,5-dicarboxylate (DMFD). And for all the copolyesters, the degree of randomness (R) was close to 1, indicating their randomness. Their thermal and mechanical properties were investigated by Differential Scanning Calorimeter (DSC) and tensile testing, results showed that the crystallizability, tensile modulus and strength of PECFs were decreased with the increasing content of CHDM at first (0–59%), and with the introduction of more CHDM (76–100%) units, they were increased accordingly. However the elongation at break was changed contrarily. The barrier properties study demonstrated that although the O2 and CO2 permeability of PEF was increased by the introduction of CHDM, PECF-32 and PECF-76 still showed excellent barrier properties, which were better or comparable to those of PEN and PEI.

Fully biobased multiblock copolymers of furan-aromatic polyester and dimerized fatty acid: Synthesis and characterization

A series of poly(trimethylene 2,5-furandicarboxylate – block – dimerized fatty acid) (PTF-b-FADD) copolymers was synthesized from 2,5-furandicarboxylic acid (FDCA), 1,3-propanediol (1,3-PD) and dimerized fatty acid diol (FADD) via a polycondensation in melt. The copolymers were characterized in regard of their chemical structure, microstructure, thermal transitions, thermal stability, and mechanical performance. A detailed analysis of PTF-b-FADDs confirmed their multiblocked structure with randomly distributed rigid and flexible segments, while their microstructure indicated its heterogeneous nature with one continuous FADD/PTF blended phase, and the phase separation forced by the PTF crystalline domains. As the result the furan-aromatic copolyesters reveal the features of thermoplastic elastomers with the phase transition temperatures, thermal and mechanical properties governed by PTF to FADD ratio. All of the monomers used for copolymers' synthesis were plant-derived, what makes PTF-block-FADDs 100% bio-based polymeric materials.