Dimethyl Furan-2,5-dicarboxylate Research Articles

Recent Trends in the Synthesis of Monomers for Furanoate Polyesters and Their Nanocomposites’ Fabrication as a Sustainable Packaging Material

Furanoate polyesters are an extremely promising new class of materials for packaging applications, particularly furanoate-based nanocomposites, which have gained a high interest level in research and development in both academia and industries. The monomers utilised for the synthesis of furanoate-based polyesters were derived from lignocellulosic biomass, which is essential for both eco-friendliness and sustainability. Also, these polyesters have a lower carbon footprint compared to fossil-based plastics, contributing to greenhouse gas reduction. The furanoate-based nanocomposites exhibit enhanced performance characteristics, such as high thermal stability, excellent mechanical strength, superior barrier resistance, and good bacteriostatic rate, making them suitable for a wide range of industrial applications, especially for food-packaging applications. This paper reviews the recent trends in the synthesis routes of monomers, such as the various catalytic activities involved in the oxidation of 5(hydroxymethyl)furfural (HMF) into 2,5-furandicarboxylic acid (FDCA) and its ester, dimethyl furan-2,5-dicarboxylate (DMFD). In addition, this review explores the fabrication of different furanoate-based nanocomposites prepared by in situ polymerization, by melt mixing or solvent evaporation methods, and by using different types of nanoparticles to enhance the overall material properties of the resulting nanocomposites. Emphasis was given to presenting the effect of these nanoparticles on the furanoate polyester’s properties.

Biobased high barrier copolyesters derived from furandicarboxylic acid and citric acid

Biobased feedstocks developed from renewable resources play a crucial role in polymers. Dimethyl octahydro-2,5-pentalenediol (MeOPD) with excellent thermal stability and rigidity is a biobased bicyclic diol derived from citric acid. In this work, MeOPD was first reacted with dimethyl carbonate (DMC) to form oligo (dimethyl octahydro-2,5-pentalenediol carbonate) (OMC). Subsequently, a series of poly(butylene-co-dimethyl octahydro-2,5-pentalenediol furanoate-co-carbonate) (PBMFC) polyesters with MeOPD units ranging from 5 to 31 mol% were synthesized via melt polycondensation from OMC, dimethyl furan-2,5-dicarboxylate (DMFD) and 1,4-butanediol (BDO). Due to the low reactivity of MeOPD, its actual content in copolymer is much lower than that in the feed, and as the MeOPD content rises, the number-average molecular weight of PBMFCs drops from 25,200 g/mol of PBMFC5 to 12,800 g/mol of PBMFC31. Despite the presence of MC units weakens thermal stability, PBMFCs still maintain good thermal stability, evidenced by Td,5% ranging from 294-325 °C in N2 and from 295-339 °C in air. The mechanical properties are also satisfactory, exhibiting tensile modulus ≥ 500 MPa, tensile strength ≥ 23 MPa, and elongation at break ≥ 150 %. Compared to PET, PBMFCs demonstrate commendable gas barrier properties, with CO2 and O2 barrier capability being 4.7–11.0 times and 2.0–3.6 times that of PET, respectively. All results indicate that PBMFCs can serve as a renewable potential material for packaging application.

Melting Behaviors of Bio-Based Poly(propylene 2,5-furan dicarboxylate)-b-poly(ethylene glycol) Co Polymers Related to Their Crystal Morphology.

In this experiment, a series of poly(propylene 2,5-furan dicarboxylate)-b-poly(ethylene glycol) (PPFEG) copolymers with different ratios were synthesized using melt polycondensation of dimethylfuran-2,5-dicarboxylate (DMFD), 1,3-propanediol (PDO) and poly(ethylene glycol) (PEG). The effect of PEG content on the crystallization behavior of the poly(propylene 2,5-furan dicarboxylate) (PPF) copolymers was investigated. For PPF, the nucleation density of the β-crystals was higher than that of α-crystals. As Tc increases, the β crystals are suppressed more, but at Tc = 140 °C, the bulk of PPF has already been converted to α crystals, which crystallize faster at higher nucleation densities, resulting in a difference in polymer properties. For this case, we chose to add a soft segment material, PEG, which led to an early multi-melt crystallization behavior of the PPF. The addition of PEG led to a decrease in the crystallization temperature of PPF, as well as a decrease in the cold crystallization peak of PPF. From the crystalline morphology, it can be seen that the addition of PEG caused the transformation of the PPF crystalline form to occur earlier. From the crystalline morphology of PPF at 155 °C, it can be observed that the ring-banded spherical crystals of the PPF appear slowly with increasing time. With the addition of PEG, spherical crystals of the ring band appeared earlier, and even appeared first, and then disappeared slowly.

Synergetic oxidative esterification of 5-hydroxymethylfurfural using Pd-Au bimetallic nanocomposite under mild conditions

An innovative Pd and Au nanoparticles (NPs) supported polymeric matrix (PdAu@PS) as stable, heterogeneous and recyclable nanocomposite was developed for oxidative esterification of 5-hydroxymethylfurfural (5-HMF) to dimethyl-2,5-furandicarboxylate (DMFC) and methyl-5-(hydroxymethyl)furan-2-carboxylate (MHFC). The prepared nanocomposite offered DMFC (48% selectivity) and MHFC (50% selectivity) in maximum 94% conversion with 98% overall selectivity at 35 °C temperature under mild reagent conditions. In this catalytic conversion, the inter-electronic interactions existing between Pd and Au metals were proved to be responsible for extraordinary stability, reactivity and recyclability of the catalyst. The identification of intermediates through mass spectrometry and the insight of control experiments helped us in concluding the possible reaction pathway. Importantly, the bimetallic catalyst was excellently recycled for six cycles with slight loss in conversion and selectivity.

High performance biobased poly(ethylene 2,5-furandicarboxylate) nanocomposites for food and cosmetics packaging materials: PMDA chain extended and TiO2 NPs functionalized

Poly (ethylene 2,5-furandicarboxylate) (PEF) has attracted more attention due to its excellent properties and great potential to be the substitute of the petroleum-based polyethylene terephthalate (PET). However, the improvement of toughness and functionality from nano materials were limited. Here, we prepared novel PEF/TiO2 nanocomposites from dimethyl 2,5-furandicarboxylate (DMFD), ethylene glycol (EG), pyromellitic dianhydride (PMDA) and TiO2 nanoparticles via one-pot polycondensation. The optimized PMDA (5‰ mol/mol of DMFD), TiO2 (60 nm, 0.5-10‰ wt./wt. of PEF) or TiO2 (30 nm or 100 nm, 3‰) served as extender, fillers, and comparison, respectively. The Tgs (∼88 °C) and the thermal stability of all nanocomposites were higher than pure PEF. The crystallization rate of the nanocomposites (60 nm-TiO2, 3‰) was improved mostly, and its half-crystallization time (t1/2) decreased to 6.16 min at 160 °C. The impact strength of nanocomposites (60 nm-TiO2, 10‰) could reach to 52.2 × 103 J/m2. Interestingly, the ultraviolet and blue-light shielding of PEF/TiO2 nanocomposites increased from 45.4% to 93.5% and 21.5% to 74.3%, respectively. The antibacterial activity of nanocomposites against E. coli also increased to 83%. The maximum migration of Ti during 35 d was 1.82 µg/g (FDA and EU guidance level are 10 µg/g). PEF/TiO2 nanocomposites shown great potential in industrial production and application.

High-Barrier Biobased Copolyesters with Targeted Glass Transition Temperatures as Renewable Alternatives for PET

A series of amorphous furan-based copolyesters were investigated with the goal of matching the glass transition temperature (Tg) of poly(ethylene terephthalate) (PET) while providing an enhanced O2 barrier. The biobased copolyesters were composed of dimethyl 5,5′-sulfanediyldi(furan-2-carboxylate) (DM-SFA) with either dimethyl 2,5-furandicarboxylate (DM-FDCA) or dimethyl 2,2′-bifuran-5,5′-dicarboxylate (DM-BFDCA) as the main monomers with ethylene glycol as the diol component. The furfural-based monomers DM-SFA and DM-BFDCA in roughly equimolar ratios provided copolyesters with Tg in the range of PET, while also having low O2 and UV-light permeabilities. With the 5-hydroxymethylfurfural-based DM-FDCA monomer, DM-SFA was adjusted to be the minor comonomer in the feed in order to provide PET-like Tg for the copolyester. On the other hand, the O2 permeabilities of these copolyesters were substantially lower, although the DM-FDCA monomer lacked the UV-blocking benefits of DM-BFDCA. Finally, isosorbide (IS) was also investigated as a possible Tg-enhancing comonomer in conjunction with ethylene glycol and DM-SFA. However, thermal stability of the IS-containing copolyester was found to be lower, as indicated by thermogravimetric analysis. Incomplete dissolution after polycondensation was also observed, which was consistent with cross-linking under high-temperature conditions. Additionally, melt-pressed films did not completely yield at high temperatures during dynamic mechanical analysis, which contrasted with the behavior of the DM-FDCA and DM-BFDCA copolyesters. The DM-SFA/DM-BFDCA copolyesters were identified as especially interesting materials having relatively high glass transition temperatures while being completely amorphous and providing films with low O2 and UV-light permeabilities. They are also notable for having most of their carbon derived from the renewable platform chemical furfural.

High-Performance Thermoplastics from a Unique Bicyclic Lignin-Derived Diol.

Polyesters are an important class of thermoplastic polymers, and there is a clear demand to find high-performing, recyclable, and renewable alternatives. In this contribution, we describe a range of fully bio-based polyesters obtained upon the polycondensation of the lignin-derived bicyclic diol 4,4'-methylenebiscyclohexanol (MBC) with various cellulose-derived diesters. Interestingly, the use of MBC in combination with either dimethyl terephthalate (DMTA) or dimethyl furan-2,5-dicarboxylate (DMFD) resulted in polymers with industrially relevant glass transition temperatures in the 103-142 °C range and high decomposition temperatures (261-365 °C range). Since MBC is obtained as a mixture of three distinct isomers, in-depth NMR-based structural characterization of the MBC isomers and thereof derived polymers is provided. Moreover, a practical method for the separation of all MBC isomers is presented. Interestingly, clear effects on the glass transition, melting, and decomposition temperatures, as well as polymer solubility, were evidenced with the use of isomerically pure MBC. Importantly, the polyesters can be efficiently depolymerized by methanolysis with an MBC diol recovery yield of up to 90%. The catalytic hydrodeoxygenation of the recovered MBC into two high-performance specific jet fuel additives was demonstrated as an attractive end-of-life option.

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

A more 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 a 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 size exclusion chromatography (SEC) 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) and dynamic mechanical analysis (DMTA) of furan-based copolyesters indicated their potential for medical packaging.

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.

Greener Synthesis Route for Furanic-Aliphatic Polyester: Enzymatic Polymerization in Ionic Liquids and Deep Eutectic Solvents

The development of bio-based polymers is growing not only due to their abundance in nature but also mainly because of the current issues with fossil-based plastics. Enzymatic polymerizations are a promising way to produce such polymers since they are known to be environmentally friendly. Sustainable polymers that require a greener production process can be realized easily via this polymerization route. However, the use of organic solvents is often one of the drawbacks in developing pathways toward fully green enzymatic polymerization methods. Therefore, in the present work, a series of fully bio-based polyesters based on 2,5-furandicarboxylic acid (FDCA), namely, furanic-aliphatic polyesters (FPEs), were enzymatically synthesized using greener solvents, such as ionic liquids (ILs) and deep eutectic solvents (DESs). The enzymatic polymerization in ILs and DESs effectively leads to the FDCA-based polyesters without any byproduct, which frequently causes coloration using traditional polymerization methods. FPEs with Mw up to 5.4 kg mol–1 were successfully achieved by Novozyme 435-catalyzed polycondensation of dimethyl 2,5-furandicarboxylate (DMFDCA) with aliphatic diols in BMIMPF6. Polymerization in DESs was also successfully conducted, resulting in the synthesis of bio-based polyesters, which can be further functionalized. Characterization using TGA, DSC, and WAXD showed that all obtained FPEs are semi-crystalline materials, which decomposed around 390 °C with a Tm of 68–123 °C and Tg of 3–12 °C. With this, we successfully developed more eco-friendly enzymatic synthesis routes for the production of sustainable polyesters

The Properties of Poly(ester amide)s Based on Dimethyl 2,5-Furanedicarboxylate as a Function of Methylene Sequence Length in Polymer Backbone.

A series of poly(ester amide)s based on dimethyl furan 2,5-dicarboxylate (DMFDC), 1,3-propanediol (PDO), 1,6-hexylene glycol (HDO), and 1,3-diaminopropane (DAP) were synthesized via two-step melt polycondensation. The phase transition temperatures and structure of the polymers were studied by differential scanning calorimetry (DSC). The positron annihilation lifetime spectroscopy (PALS) measurement was carried out to investigate the free volume. In addition, the mechanical properties of two series of poly(ester amide)s were analyzed. The increase in the number of methylene groups in the polymer backbone resulted in a decrease in the values of the transition temperatures. Depending on the number of methylene groups and the content of the poly(propylene furanamide) (PPAF), both semi-crystalline and amorphous copolymers were obtained. The free volume value increased with a greater number of methylene groups in the polymer backbone. Moreover, with a lower number of methylene groups, the value of the Young modulus and stress at break increased.

WITHDRAWN: 2,5-Furandicarboxylic acid based polyamide membrane

2,5-furandicarboxylic acid (FDCA) has the similar structure with terephthalic acid, and it can be used in the preparation of new furan-based polyamide materials to replace petroleum-based monomer. In present work, polyfuran dicarboxylate decane diamine (PA10F) was prepared from dimethyl 2,5-furandicarboxylate (DMFDCA) and 1,10-diaminodecane, and using PA10F (Mw = 3.3 × 10 4 ) as raw material. And then DMF as solvent and water as coagulation bath, PA10F membranes with asymmetric structure were fabricated by non-solvent induced phase separation (NIPS) from different concentration of PA10F casting solution. The performance of PA10F membrane was studied on the morphology, roughness, surface charge, reject rate and anti-protein contamination. The results show that the surface of PA10F is negatively charged, and the rejection rates of methyl blue (MB, Mr = 799.80), Congo red (CR, Mr = 696.68) and acid fuchsin (AF, Mr = 585.54) with different molecular sizes can reach 100%, 99.06% and 98.01%, respectively. Furthermore, PA10F membrane shows an excellent anti-fouling performance, and the flux recovery rate can reach 94.01%. • PA10F was prepared from dimethyl 2,5-furandicarboxylate and 1,10-diaminodecane. • PA10F membranes were fabricated by non-solvent induced phase separation. • PA10F membrane was a kind of asymmetric membrane with negatively charged surface. • PA10F membrane shows an high anti-fouling performance with nano layered top surface. • Supporting layer is a finger hole structure with the sponge structure bottom surface.

Dimethyl 2,5-furandicarboxylate synthesis from 2,5-furanodicarboxylic acid and dimethyl carbonate in presence of MgO-Al2O3 and tetrabutylammonium bromide

• MgO-Al 2 O 3 and MgO-La 2 O 3 bimetallic oxides were prepared by a simple hydrothermal method. • An 80.19% selectivity of DMFDCA was obtained under mild conditions. • This work provides a green and economical route for DMFDCA production. 2,5-furandicarboxylic acid (FDCA) and dimethyl 2,5-furandicarboxylate (DMFDCA) are attracting increasing attention as important biomass-based chemical feedstocks. Considering the physicochemical properties of FDCA with high polarity, poor solubility and easy decarboxylation, the synthesis of DMFDCA from FDCA is especially necessary. However, how to synthesize DMFDCA in case of avoiding a series of side reactions such as furan ring opening and double bond addition is a huge challenge. Herein, we used FDCA and dimethyl carbonate (DMC) to synthesize DMFDCA in presence of MgO-Al 2 O 3 and tetrabutylammonium bromide (TBAB), and the optimized yield and selectivity of DMFDCA came up to 76.38% and 80.19%, respectively. In addition, the used catalysts were characterized by SEM, XRD, BET, XPS and CO 2 -TPD analysis, and the structure, composition, morphology and basic site distribution of catalyst were well studied, and the relationship between catalyst structure and catalytic performance in the esterification of FDCA into DMFDCA thorough organic acid exchange reaction method was also analyzed. This work provides a promising solution for the preparation of furan-based polyester monomers.

Insights into high molecular weight poly(ethylene 2,5-furandicarboxylate) with satisfactory appearance: Roles of in-situ catalysis of metal zinc

In pursuit of poly(ethylene 2,5-furandicarboxylate) PEF materials with high molecular weight, satisfactory appearance and faster crystallization rate, its preparation from dimethyl furan-2,5-dicarboxylate (DMFD) with ethylene glycol (EG) in the trace presence of metal zinc was performed via transesterification method. Optimization of the main polymerization parameters enabled Zn-catalyzed PEF to gain high molecular weight (Mn, 5.40×104gmol−1) and low content of diethylene glycol furandicarboxylate unit (DEGF, 2.91%). On the basis of experimental phenomena and high performance liquid chromatography (HPLC), the actual catalytic active species of metal zinc in the polymerization was speculated to be a salt of 2, 5-furandicarboxylate derivative (Zn(II)). The in-stiu catalyst can efficaciously inhibit the influence of by-product FDCA on the color of PEF, which displayed quite better appearance (close to white). Differential Scanning Calorimetry (DSC) showed that the in-stiu catalytic system acted as nucleating agent (NA) and the crystallization half-time (t1/2) of PEFs-Zn was only 1/4 of that of PEF-tin. Additionally, series of high molecular weight furan-based polyesters from DMFD and diols with different methylene (3, 5, 6 and 8) were obtained by zinc powder as in-stiu catalyst, which further evidenced it to be efficiency and universality.

On the way to greener furanic-aliphatic poly(ester amide)s: Enzymatic polymerization in ionic liquid

The polymerization of 2,5-furandicarboxylic acid (FDCA), one of the key building blocks for the preparation of furan polymers, is often accompanied with side reactions (e.g. decarboxylation). Due to the mild reaction conditions, enzymatic polymerizations became an excellent candidate to address this issue. Here, we present a green and effective method to prepare different furanic-aliphatic poly(ester amide)s (PEAFs) by applying two different approaches. PEAFs with Mw‾ up to 21 kg mol−1 were successfully synthesized by a Novozyme 435-catalyzed polycondensation of dimethyl 2,5-furandicarboxylate (DMFDCA) with aliphatic diols, diamines or amino alcohols, using toluene at 90 °C. Additionally, we were able to enhance the sustainability of the entire process by performing the polymerization in ionic liquids – BMIMPF6 and EMIMBF4. Using the ionic liquids (ILs) BMIMPF6 and EMIMBF4 as solvents, we were able to produce PEAFs with Mw‾ up to 7 kg mol−1. The different polarity of the solvents affects the enzyme activity and product solubility, thus also the final molecular weight of the PEAFs. Despite the lower molecular weight, the tested ILs result products with similar characteristics. All obtained PEAFs are semi-crystalline materials and decompose at a temperature around 390 °C with a Tm of around 77–140 °C and Tg of around 11–46 °C. Although still exemplified on the proof-of-concept production of sustainable materials, these findings pave the way to promote the transition from fossil-to bio-based polymers, as well as more environmentally friendly synthetic routes.

Modification of poly(ethylene 2,5-furandicarboxylate) with aliphatic polycarbonate diols: 1. Randomnized copolymers with significantly improved ductility and high CO2 barrier performance

Poly(ethylene 2,5-furandicarboxylate) (PEF) is a very promising biobased polymer possessing very high mechanical strength, rigidity and gas barrier performance. But its poor ductility and toughness may limit its applications. In this study, PEF-based copolymers with high intrinsic viscosity were successfully synthesized via melt polycondensation of dimethyl 2,5-furandicarboxylate (DMFD) and ethylene glycol in the presence of a copolycarbonate diol (PPeHC diol) as produced from 1,5-pentylene diol (PeDO), 1,6-hexylene diol (HDO) and dimethyl carbonate, and characterized with 1H NMR, 13C NMR, DSC, TGA, tensile, impact and gas barrier testing. The products were “randomnized” as a result of ester-carbonate exchange reaction occurring along melt polycondensation, and therefore became amorphous copolymers possessing composition-dependent physico-mechanical properties which can be tunable from rigid-to-ductile thermoplastics to thermoplastic elastomers. Particularily, the copolymers with φPPeHC of 25 wt% and 30 wt% are thermoplastics possessing greatly improved ductility (elongation at break up to 194%) and CO2 barrier performance higher than poly(ethylene terephthalate) (PET; BIFCO2 3.6–2.8), and retaining high tensile modulus (2.2–1.9 GPa) and yielding strength (69–58 MPa) comparable to the bottle-grade PET. In comparison, the copolymer with φPPeHC of 40 wt% behaves as a high performance thermoplastic elastomer with excellent gas barrier performance as well as high tensile strength (23 MPa).

Biocatalytic Synthesis of Furan-Based Oligomer Diols with Enhanced End-Group Fidelity

The lipase-catalyzed synthesis of furan-comprising polyester oligomer diols (α,ω-telechelic diols) is reported. Oligofuranoate diols with excellent end-group fidelity and a yield of 95% were synthesized using a solvent-free two-stage polycondensation of dimethyl furan-2,5-dicarboxylate (DMFDCA) and 1,4-cyclohexanedimethanol (1,4-CHDM) using immobilized Candida antarctica Lipase B (CalB). Recycling of immobilized CalB to further decrease the production cost is successfully demonstrated. However, it showed limitation in the product yield that decreases ±20% with each additional reuse. The synthetic procedure has been scaled up, easily opening the possibility to use the developed diols in industrial polycondensations utilizing the excellent flame retardancy property and high thermal stability typical for furan-based polymers.

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 (Mw) 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 (Tg) 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 ...

Diels-Alder cycloaddition of oxidized furans and ethylene over supported heteropolyacid catalysts for renewable terephthalic acid

Abstract The Diels-Alder reaction of biomass-derived dimethyl 2,5-furandicarboxylate (DMFDC) with ethylene followed by dehydrative aromatization is a sustainable route for the production of terephthalic acid, a monomer used for the synthesis of polyethylene terephthalate (PET). In this work, a series of heteropolyacid (HPA) catalysts with different supports, in this case SiO2, TiO2 and ZrO2, and hetero-addenda atoms, here phosphotungstic acid (HPW), silicotungstic acid (HSiW) and phosphomolybdic acid (HPMo), were used as catalysts, and their structure-activity correlation in the conversion of DMFDC to terephthalate was examined based on the density and strength of the acid sites. Characterization by XRD and Raman indicated that the Keggin structures of HPAs were well preserved on the SiO2 support compared to other supports, resulting in strong Bronsted acidity. The silica-supported HPW and HSiW catalysts exhibited significantly higher activity for terephthalate production than other supports and HPMo catalysts, but their activity were not correlated with the total acidity as measured by NH3-TPD. In contrast, the catalyst acid strength, as determined by the NH3 desorption temperature, decreased in the order HPW/SiO2 > HSiW/SiO2 >> HPW/ZrO2 > HPW/TiO2 > HPMo/SiO2 and was well correlated with the turnover rate for terephthalate production, suggesting that the higher activity of HPW/SiO2 is at least partly due to its stronger Bronsted acidity and that promoting the dehydration step of this reaction is a key to improving the selectivity to terephthalate. The effects of reaction conditions, in this case the acid loading amount, solvent used, temperature, and time, were also investigated with the most active silica-supported HPW catalysts to optimize the terephthalate yield. The 25%-HPW/SiO2 catalyst demonstrated a remarkable terephthalate yield of ∼60% with almost complete conversion under the optimum condition.

Furan-Based Copolyesters from Renewable Resources: Enzymatic Synthesis and Properties.

Enzymatic polymerization provides an excellent opportunity for the conversion of renewable resources into polymeric materials in an effective and sustainable manner. A series of furan‐based copolyesters was synthesized with Mw‾ up to 35 kg mol−1, by using Novozyme 435 as a biocatalyst and dimethyl 2,5‐furandicarboxylate (DMFDCA), 2,5‐bis(hydroxymethyl)furan (BHMF), aliphatic linear diols, and diacid ethyl esters as monomers. The synthetic mechanism was evaluated by the variation of aliphatic linear monomers and their feed compositions. Interestingly, there was a significant decrease in the molecular weight if the aliphatic monomers were changed from diols to diacid ethyl esters. The obtained copolyesters were thoroughly characterized and compared with their polyester analogs. These findings provide a closer insight into the application of enzymatic polymerization techniques in designing sustainable high‐performance polymers.