Search Results (84)

In recent years, the unsustainable consumption of fossil resources has been causing major ecological concerns, especially for the production of polymeric materials. 2,5-furandicarboxylic acid (FDCA) is one of the most appealing biobased chemical building blocks, because of its potential to replace the industrially widespread petrochemical, terephthalic acid. Camphoric acid (CA) is also an interesting biobased chemical derived from camphor, one of the most widespread fragrances. This work had the objective of combining CA, FDCA and biobased 1,6-hexanediol to synthesize random copolymers for sustainable food packaging applications by means of a solvent-free polycondensation process, obtaining poly(hexamethylene furanoate-co-camphorate)s (PHFC). The optimization of the synthesis made it possible to obtain high molecular weight polyesters with a percentage of camphoric acid up to 17 mol%, which could be compression-molded into films. They were subjected to molecular, structural, thermal and functional characterization via NMR, GPC, WAXS, DSC, and TGA analyses, as well as mechanical and gas permeability tests. Compared to the homopolymer of reference, it was possible to obtain higher flexibility, 430% higher elongation at break, and 223% higher toughness, with comparable, excellent gas permeability properties. Calorimetric evidence suggested that camphoric acid might have enhanced the formation of a partially ordered mesomorph phase in the copolymers under study. Full article

The nano-metal oxide-catalyzed oxidation of 5-hydroxymethylfurfural (HMF) with sodium hypochlorite (NaClO) is an effective and mild technique for synthesizing 2,5-furanediformic acid (FDCA). However, the rapid and large-scale separation of nanocatalysts remains a major challenge. In this study, we developed a magnetic and recyclable copper oxide-based catalyst supported on the mechanochemically synthesized Fe₃O₄. Benefiting from the introduction of the Fe₃O₄ carrier and cetyltrimethylammonium bromide (CTAB) surfactant, the CuO-CTAB/Fe₃O₄ catalyst owns smaller CuO particle sizes, which endows it with excellent catalytic activity in the oxidation of HMF, achieving a high FDCA yield of 90.3%. Furthermore, the rapid magnetic separation of the catalyst effectively inhibits the excessive conversion of FDCA. The recovered catalyst can be reused for at least five cycles without significant loss of catalytic performance, confirming the promising application prospect of the CuO-CTAB/Fe₃O₄ catalyst. Full article

2,5-furandicarboxylic acid (FDCA), a high-value biomass-derived monomer, serves as a crucial building block for sustainable polymers including polyesters, polyamides, and polyurethanes. This study systematically investigated the catalytic oxidation of 5-hydroxymethylfurfural (HMF) to FDCA over Pt/Al₂O₃ and Pt–Bi/Al₂O₃ catalysts. The 5Pt/Al₂O₃ catalyst yielded 60.6% FDCA after 12 h under optimized conditions (80 °C, 0.1 MPa O₂, 1 equiv. Na₂CO₃). Remarkably, Bi-modified 5Pt–1Bi/Al₂O₃ catalyst dramatically enhanced catalytic performance, achieving 94.1% FDCA yield within 6 h under optimized conditions (80 °C, 1.5 MPa O₂, 2 equiv. Na₂CO₃). Comprehensive characterization revealed that the exceptional activity originates from Bi–O–Pt interactions that modulate the electronic structure and oxidation state of Pt active sites, which facilitates the oxidation of intermediate 5-formyl-2-furancarboxylic acid (FFCA) to FDCA, the rate-limiting step of HMF oxidation. This work demonstrates an efficient Bi-promoted Pt catalytic system for FDCA production with significant potential for industrial application. Full article

Alkyd resins (ARs) represent a significant development in synthetic polymers, being among the oldest ones and playing a crucial role in numerous applications, especially within the coating sector. The trend is moving towards replacing non-renewable resources in the production of ARs with bio-based alternatives, with the goal of creating more sustainable binder materials as part of the transition to a bioeconomy. 2,5-Furandicarboxylic acid (FDCA) serves as a promising biomass-derived “building block” to replace non-renewable petroleum-derived aromatic diacids and anhydrides in AR synthesis. Various vegetable oils, including sunflower seed (SFO) and linseed oils (LSO), were utilized along with pentaerythritol (P) and glycerol (G) as polyols. FTIR and ¹H NMR spectroscopies were conducted for the verification of alkyd structures. The synthesized ARs were assessed for their physico-chemical properties, including acid value, hydroxyl value, color, density, and viscosity. The performance of the resulting alkyd coatings, which are crucial for their commercial applications, was examined. Key factors such as drying time, hardness, adhesion, wettability, chemical and corrosion resistance, and UV stability were analyzed. All synthesized FDCA-based alkyd coatings demonstrate outstanding adhesion, good thermal stability up to 220 °C, and barrier properties for steel with |Z|_0.02Hz ~10⁶–10⁷ Ohm cm⁻², which render them suitable for the processing requirements of indoor coating applications. The higher temperature at 50% mass loss (T₅₀) for SFO-P (397 °C) and LSO-P (413 °C) as compared to SFO-G (380 °C) and LSO-G (394 °C) indicated greater resistance to thermal breakdown when pentaerythritol was used as a polyol. Replacing glycerol with pentaerythritol in FDCA-based ARs resulted in a viscosity increase of 1.2–2.4 times and an enhancement in hardness from 2H to 3H. FDCA-based ARs exhibited decreased tack-free time, enhanced thermomechanical properties, and similar hardness as compared to phthalic anhydride-based ARs, underscoring the potential of FDCA as a sustainable alternative to phthalic anhydride in the formulation of ARs, integrating a greater proportion of renewable components for wood coating applications. Full article

In this study, the transformation of 2,5-furandicarboxylic acid (FDCA) to 2,5-bis(aminomethyl)furan (BAMF) is proposed and investigated for the first time. Using FDCA as the substrate, the process involves two key steps: first, converting FDCA to 2,5-dicyanofuran (DCF) via carboxy-cyanation, followed by the heterogeneous catalytic hydrogenation of DCF to produce BAMF. For the carboxy-cyanation, two ammoniation routes were compared, including the molten ammoniated dehydration route and the moderate ammoniated dehydration route. The difference between the ammoniation of bio-based cyclic dicarboxylic acid and that of petroleum-based aliphatic dicarboxylic acid was discovered. A moderate ammoniated dehydration route that is more suitable for bio-based cyclic dicarboxylic acid has been developed. SOCl₂ was found to effectively activate the stable carboxyl group and act as a dehydrating agent, facilitating the dehydration of the intermediate 2,5-furandicarboxamide (FDAM) to DCF with higher efficiency. For the hydrogenation reaction of DCF, Raney Co exhibited excellent catalytic performance, achieving a 94.5% yield of BAMF from DCF. Based on industrial practice, this research represents the first exploration of the pathway from bio-based FDCA to BAMF, which opens a new line for the sustainable production of bio-based diamines. Full article

Aiming to address the key challenges of poor enzyme stability, difficult recovery, and difficult synergistic optimization of catalytic efficiency in high-value conversion of biomass, this study utilizes mineralization self-assembly technology to combine laccase with Fe₃O₄@SiO₂-PMIDA-Cu²⁺ composite, constructing magnetic laccase nanoflower (MLac-NFs) materials with a porous structure and superparamagnetism. This synthetic material can efficiently catalyze the selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA). The characterization results indicated that MLac-NFs exhibit optimal catalytic activity (63.4 U mg⁻¹) under conditions of pH 6.0 and 40 °C, with significantly enhanced storage stability (retaining 94.26% of activity after 30 days of storage at 4 °C). Apparent kinetic analysis reveals that the substrate affinity and maximum reaction rate of MLac-NFs were increased by 38.3% and 439.6%, respectively. In the laccase–mediator system (LMS), MLac-NFs mediated by 30 mM TEMPO could achieve complete conversion of HMF to FDCA within 24 h. Moreover, due to the introduction of magnetic nanoparticles, the MLac-NFs could be recovered and reused via an external magnetic field, maintaining 53.26% of the initial FDCA yield after six cycles. Full article

2,5-Furandicarboxylic acid (FDCA) is a bio-based platform chemical with high potential to replace terephthalic acid in polymer production, particularly for polyethylene furanoate (PEF), a biopolymer with superior thermal and barrier properties. This study investigates the selective oxidation of 5-hydroxymethylfurfural (HMF) into FDCA using nickel-based heterogeneous catalysts, aiming at a cost-effective and sustainable alternative to noble metal catalysts. A series of nickel oxide catalysts were synthesized and screened. The NiOx catalyst synthesized without thermal treatment via Route B showed the best performance, achieving a FDCA yield of 11.77%, selectivity of 27.41%, and concentration of 0.9 g/L under preliminary conditions. Reaction kinetics revealed that the controlled addition of NaClO enhanced FDCA yield by 2.28 times. Optimization using a 2³ factorial design identified the optimal conditions as 6% (w/v) catalyst concentration, 25 °C, and a NaClO:HMF molar ratio of 12:1, leading to 34.14% yield and 42.57% selectivity. The NiOx catalyst maintained its activity over five successive cycles, indicating good recyclability. Moreover, NiOx demonstrated catalytic activity with crude HMF derived from glucose dehydration, confirming its practical applicability. These results support the potential of nickel-based catalysts in sustainable FDCA production, contributing to the advancement of bio-based polymer synthesis. Full article

The need for renewable alternatives to petroleum-based polymers is growing in response to environmental concerns and resource depletion. Polyimides (PIs), which are traditionally synthesized from petroleum-derived monomers, raise sustainability issues. In this work, renewable 2,5-furandicarboxylic acid (FDCA) was employed as a sustainable feedstock to synthesize a bio-based diamine monomer, N,N′-bis(4-aminophenyl)furan-2,5-dicarboxamide (FPA). Subsequently, FPA was polymerized with various aromatic dianhydrides through thermal imidization, yielding four distinct bio-based polyimide (FPA-PI) films. The resulting films exhibited exceptional thermal stability, with 5% weight loss temperatures exceeding 425 °C and char yields ranging from 54% to 60%. Mechanical characterization revealed high elastic moduli (2.14–3.20 GPa), moderate tensile strengths (50–99 MPa), and favorable aging resistance. Gas permeation tests demonstrated promising CO₂/N₂ separation performance, with FPA-DODDA achieving superior CO₂/N₂ selectivity (27.721) compared to commercial films such as Matrimid^®, polysulfone, and polycarbonate, while FPA-BPFLDA exhibited enhanced CO₂ permeability (P(CO₂) = 2.526 Barrer), surpassing that of Torlon^®. The CO₂/N₂ separation performance of these FPA-PI films is governed synergistically by size-sieving effects and solution-diffusion mechanisms. This work not only introduces a novel synthetic route for bio-based polymers but also highlights the potential of replacing conventional petroleum-based materials with renewable alternatives in high-temperature and gas separation applications, thereby advancing environmental sustainability. Full article

Metal carbonyl clusters, which can be seen as monodispersed and atomically defined nanoparticles stabilized by CO ligands, were used to prepare Ru-based catalysts with tuned basic properties to conduct the 5-hydroxymethylfurfural (HMF) aerobic oxidation to produce 2,5-furandicarboxylic acid (FDCA) in base-free conditions. The controlled decomposition of the carbonyl cluster [HRu₃(CO)₁₁]⁻, a methodology not yet applied to Ru catalysts for this reaction, on different supports focusing on controlling and tuning the basic properties of support allowed the formation of small Ru nanoparticles with a mean diameter of around 1 nm. The catalytic systems obtained resulted in more activity in the HMF oxidation than those prepared through a more common salt-impregnation technique, and the deposition of Ru nanoparticles on materials with basic functionalities has allowed avoiding the use of basic solutions in the reaction. The characterization by CO₂-TPD of Mg(Al)O catalysts obtained from decomposition of layered double hydroxide hydrotalcites with different composition and activation has allowed disclosure of an important correlation between the selectivity of FDCA and the fraction of weak basic sites, which is decreased by the calcination treatment at increased temperature. Full article

In the face of the intensifying energy and environmental challenges, the exploration of clean and sustainable approaches to energy conversion and utilization holds paramount significance. 5-Hydroxymethylfurfural (HMF), as a biomass platform compound with great potential, has drawn extensive attention for its oxidation to prepare 2,5-Furandicarboxylic acid (FDCA). In this study, a CoS-doped CuS composite catalyst (CoS–CuS) was synthesized via a one-step microwave–hydrothermal method for the electrocatalytic oxidation of HMF. The catalyst was comprehensively analyzed by means of multiple characterization techniques and electrochemical testing methods. The results demonstrate that the doping of CoS optimizes the surface electronic structure of the catalyst, enhancing its adsorption capabilities for HMF and OH⁻. Compared with the CuS catalyst, CoS–CuS in the 5-hydroxymethylfurfural oxidation reaction (HMFOR) shows a lower onset potential decreasing from 1.32 V_RHE to 1.29 V_RHE. At a potential of 1.4 V_RHE, the current density of CoS–CuS attains a value 2.02-fold that of CuS. Significantly, CoS–CuS demonstrates a substantially higher Faraday efficiency in the generation of FDCA, reaching nearly 89.1%. This study provides a promising approach for the construction of other efficient copper-based electrocatalysts. Full article

5-Hydroxymethylfurfural (HMF) serves as an important bridge connecting biomass resources with fossil fuels. Its downstream product, 2,5-furandicarboxylic acid (FDCA), is a renewable alternative to terephthalic acid (TPA) in the synthesis of various polymer materials. In this study, we successfully synthesized four ruthenium-based catalysts with varying valence states supported on carbon nanotubes (CNTs) and compared the performance of HMF electrooxidation. Among these, the Ru^+2.9 catalyst demonstrated the highest activity for the electrochemical oxidation of HMF to FDCA in the neutral medium (0.1 M K₂SO₄). Notably, the FDCA yield reached 90.2% under an applied potential of 0.95 V (vs. Ag/AgCl) after 24 h. Mechanistic analysis revealed that the superior specific capacitance of the Ru^+2.9 catalyst significantly facilitated the reaction process. This work represents a more cost-effective approach to avoid the need for excessive alkaline additives during catalyst preparation and the HMF oxidation process, and FDCA separated easily after cooling the reaction solution down. Full article

Hydroxymethylfurfural (HMF) is a substance produced in sugar-rich foods through the Maillard reaction or thermal degradation. It has been shown that when HMF content reaches a certain dose, it causes harm to human health. In many food quality tests, the content of HMF can be used as an important indicator. Therefore, when the content of hydroxymethylfurfural in food is too high, it will cause damage to the human body. But to conserve resources, hydroxymethylfurfural in food can be converted into valuable chemicals, so as to achieve the effective use of resources. It has been shown that foods rich in fructose and glucose can be easily transformed into HMF. Therefore, it is necessary and important to study the conversion pathway of hydroxymethylfurfural in foods. 2, 5 furandicarboxylic acid (FDCA) can be obtained through the HMF oxidation reaction. Due to the similarity of its structure to the polymer monomer terephthalic acid, it can be used as a renewable substitute monomer of petroleum-based terephthalic acid in the process of synthesizing food-contact materials. Therefore, it is very significant to explore the oxidation process of HMF to FDCA. Full article

In this work, the development of FDCA-based polyester resins for coil coatings in industrial environment is presented. The goal of our research was to prepare industrial coatings made from renewable materials with the same performance as the standard coating. Resins with 1%–41% of FDCA on polymer were synthesized and then used in a formulation for primer. Resins were characterized by the determination of non-volatile matter, acid value, hydroxyl value, glass transition temperature, and measurement of viscosity, color and molecular weight. Coatings were characterized by the determination of viscosity, density, non-volatile matter, adhesion, T-test, MEK test, reverse impact, and pencil hardness, as well as the measurement of gloss. FTIR measurements confirmed successful incorporation of FDCA into the polymer. The results showed that resins with up to 31% of FDCA on polymer can be used to prepare coil coating where the properties of resins comply with the requirements and are comparable to the properties of standard resin. Resins had non-volatile matter between 59.0 and 60.1%, an acid value up to 4.6 mg KOH/g, a hydroxyl value of 22.0–24.9 mg KOH/g and viscosity at 23 °C between 6100 and 7500 mPa.s. Nevertheless, with the increase in FDCA in the formulation, discoloration of the resin occurred and incompatibility with the solvents was observed, while up to 10 °C lower glass transition temperatures and up to 28% lower molecular weights of the resins were determined. For coatings prepared from FDCA-based resins, the properties improved or were comparable to the properties of coating prepared from standard resin. Adhesion improved with higher content of FDCA in the resin from 2 Gt to 0 Gt, while all coatings had gloss at 60° of 39%–41%, a reverse impact of 10 J and a pencil hardness of H/2H. T-bend test results varied between 2 T and 0.5 T and the results of the MEK test showed resistance > 100 DR. Full article

As a type of sustainable and renewable natural source, biomass-derived 5-hydroxymethyl furfural (HMF) can be converted into high-value chemicals. This study investigated the interactions between silver (Ag) and oxide supports with varied reducibility and their contributions to tuning catalytic performance in the selective oxidation of HMF. Three representatives of manganese dioxide (MnO₂), zirconium dioxide (ZrO₂), and silicon dioxide (SiO₂) were selected to support the Ag active sites. The catalysts were characterized by techniques such as STEM (TEM), Raman, XPS, H₂-TPR, and FT-IR spectroscopy to explore the morphology, Ag dispersion, surface properties, and electronic states. The catalytic results demonstrated that MnO₂ with the highest reducibility exhibited superior catalytic performance, achieving 75.4% of HMF conversion and 41.6% of selectivity for 2,5-furandicarboxylic acid (FDCA) at 120 °C. In contrast, ZrO₂ and SiO₂ exhibited limited oxidation capabilities, mainly producing intermediate products like FFCA and/or HMFCA. The oxidation ability of these catalysts was governed by support reducibility, because it determined the density of oxygen vacancies (Ov) and surface hydroxyl groups (O_OH), and eventually influenced the catalytic activity, as demonstrated by the reaction rate: Ag/MnO₂ (3214.5 mol_HMF·g_Ag⁻¹·h⁻¹), Ag/ZrO₂ (2062.3 mol_HMF·g_Ag⁻¹·h⁻¹), and Ag/SiO₂ (1394.4 mol_HMF·g_Ag⁻¹·h⁻¹). These findings provide valuable insights into the rational design of high-performance catalysts for biomass-derived chemical conversion. Full article

Lignocellulosic biomass is currently widely used in many biorefining processes. The full exploitation of biomass from uncultivated or even marginal lands for the production of biobased chemicals has deserved huge attention in the last few years. Among the sustainable biomass-based value chains, cardoon crops could be a feedstock for biorefineries as they can grow on marginal lands and be used as raw material for multipurpose exploitation, including seeds, roots, and epigeous lignocellulosic solid residue. This work focused on the technical analysis of a novel integrated flowsheet for the exploitation of the lignocellulosic fraction through the assessment of thermochemical, biochemical, and extractive technologies and processes. In particular, high-yield thermochemical processes (gasification), innovative biotechnological processes (syngas fermentation to ethanol), and extractive/catalyzed processes for the valorization of cardoon roots to FDCA and residual solid biomass were modeled and simulated. Inulin conversion to 2,5-Furandicarboxylic acid was the main conversion route taken into consideration. Finally, the novel process flowsheet, treating 130,000 t/y of residual biomass and integrating all proposed technologies, was modeled and assessed using process simulation tools to achieve overall mass and energy balances for comparison with alternative options. The results indicated that cardoon biorefining through the proposed flowsheet can produce, per 1000 tons of input dry biomass, 211 kg of 2,5-Furandicarboxylic acid and 140 kg of ethanol through biomass gasification followed by syngas fermentation. Furthermore, a pre-feasibility analysis was conducted, revealing significant and potentially disruptive results in terms of environmental impact (with 40 kt_CO2eq saved) and economic feasibility (with an annual gross profit of EUR 30 M/y). Full article