Furfurylamine Research Articles

Pd@BTL-Cd core-shell nanoparticles as plasmonic photocatalysts for the reductive amination of furfural in water.

This work reports the step-wise fabrication of a core-shell plasmonic nanocomposite Pd@BTL-Cd consisting of a BTL-Cd shell and a palladium nanoparticle core. BTL-Cd is the [Cd(BTL)·CdCl2] complex where the heptadentate framework of the bis-compartmental ligand encapsulated two Cd(II) centres in separate pockets. Pd@BTL-Cd has been found to be highly efficient for the photocatalytic conversion of furfural (a biomass-derived aldehyde) to furfuryl amine via reductive amination in aqueous ammonia at room temperature. The improved photocatalytic performance of the nanocomposite and its functioning in visible regions in contrast to parental species are attributed to the synergistic functioning of the core and the shell. The inclusion of the Cd-BTL nanoshell lowers the overall band gap of the material while the Pd nanocore generates in situ hydrogen species during photocatalysis. The optimization of catalytic conditions revealed that 10 mg of the fabricated photocatalyst can offer 99% conversion and a high turnover number in 4 h. The efficacy of the catalyst can be retained for up to 5 cycles with high selectivity for the formation of furfuryl amine (98%) in the presence of visible light (λ = 445 nm). Pd@BTL-Cd is also catalytically effective for the reductive amination of other aldehydes.

Enhanced mechanical properties of epoxy and furfuryl amine functionalized silica nanocomposites

In this work, the effect of epoxy and furfuryl amine functionalization of silica-nanoparticles on the mechanical behaviour such as tensile and flexural properties of the anhydride epoxy nanocomposites have been investigated. The sol-gel technique has been used to synthesize silica nanoparticles, followed by grafting with Epichlorohydrin (EPR) and Furfuryl amine (FA). The effect of filler loading in the epoxy nanocomposites was also studied by changing the weight percentage to 0.5, 1, and 2%. FTIR, FESEM, and TGA analyses were performed to confirm the molecular architecture, surface morphology, and thermal degradation behaviour of the functionalized nanoparticles. Tensile and flexural tests were performed to study the mechanical behaviour of the epoxy nanocomposites. The mechanical properties of the nanocomposites were found to be significantly enhanced for all the variations of nanocomposites at a filler loading of 0.5 wt.%. The maximum tensile strength and strain were improved by ∼67% and ∼71%, respectively, in the case of the control sample at 0.5 wt.% of FA functionalized nanofiller. Flexural strength, strain, and work of fracture have been enhanced by ∼81%, ∼34%, and ∼82%, respectively with respect to control sample. These improvements are related to the better interfacial adhesion between functionalized nanofiller and epoxy matrix through the covalent reaction of furfuryl amine and anhydride functional groups of the matrix system. Thus, FA functionalized silica nanoparticles have the potential to use as an admirable, cost-effective incorporation for epoxy to counter the brittle failure of the epoxy matrix.

Structures and performance of a polybenzoxazine with high heat resistance and high-frequency low-dielectric properties

Benzoxazine is a newly developed thermoset resin that has attracted significant academic and industrial interest due to its excellent properties. However, improving its dielectric performance while maintaining high heat resistant is crucial for expanding its application in 5G electronics. In this study, we designed and synthesized a novel benzoxazine monomer, DFDA-PTB, using p-tert-butylphenol (PTB) as the phenol source and furfuryl diamine (DFDA), derived from furfuryl amine, as the amine source. Two additional benzoxazines with similar structures were also synthesized for comparison. The cured product, poly(DFDA-PTB), was then analyzed to explore the relationship between its structure and properties. The results indicate that the introduction of a furan ring structure enhances thermal stability and reduces the dielectric constant. Additionally, the inclusion of tert-butyl groups further lowers the dielectric constant and dielectric loss. Simulation methods were employed to study the mechanisms behind these improvements. Poly(DFDA-PTB) demonstrated superior dielectric properties, with a dielectric constant of 2.51 and a dielectric loss of 0.0018 at 10 GHz. It also exhibited excellent heat resistance, with a char yield of 45.4 % at 800 °C. These properties make poly(DFDA-PTB) a promising candidate for electronic packaging and communication applications.

Surface Acidic Species-Driven Reductive Amination of Furfural with Ru/T-ZrO2.

Catalyst development for upgrading bio-based chemicals towards primary amines has increasingly attracted owing to their applications in the pharmaceutical and polymer industries. The surface acidic sites in metal oxide-based catalysts play a key role in the reductive amination of aldehydes/ketones involving H2 and NH3; however, the crucial role of the type of surface acidic species and their strength remains unclear. Herein, this study exhibits the catalytic reductive amination of furfural (FUR) to furfurylamine (FUA) with Ru supported on tetragonal (Ru/T-ZrO2) and monoclinic (Ru/M-ZrO2) ZrO2. Ru/T-ZrO2 exhibited an 11.8-fold higher rate of reductive amination than Ru/M-ZrO2, giving a quantitative yield of FUA (99 %) at 80 °C in 2.5 h and is recyclable up to four runs. Catalyst surface investigation using spectroscopic techniques, like X-ray photoelectron, electron paramagnetic resonance, and Raman, confirm higher oxygen vacancy sites (1.6 times) on the surface of Ru/T-ZrO2 compared to Ru/M-ZrO2. Moreover, in-situ NH3-diffuse reflectance infrared Fourier transform spectroscopy studies display that Ru/T-ZrO2 has more moderate Bronsted acidic sites (surface H-bonded hydroxyl groups) than Ru/M-ZrO2. Further, the controlled experiments and poisoning studies with KSCN and 2,6-lutidine suggest the crucial role of Ov sites (Lewis acidic sites) and surface hydroxyl groups (Bronsted acidic sites) for selective FUA formation.

Solvent-free synthesis of pendant crosslinked polyurethane hot melt adhesive via dynamic Diels-Alder reaction

Pendant cross-linked polyurethane hot melt adhesive was synthesized without any solvents via Diels-Alder reaction (DA reaction) and was coded as DAPU. Firstly, a chain extender containing furan ring was synthesized via Michale addition reaction between hydroxyethyl acrylate (HEA) and furfuryl amine (FA). Secondly, the polyurethane prepolymer with pendant furan rings was synthesized from the reaction between the chain extender and isocyanate-terminated polyurethane prepolymer. Finally, the hot melt adhesive was cross-linked via DA reaction between furan rings and bismaleimide (BMI) without organic solvents due to the viscosity inhibition at higher temperature. DAPU exhibited a higher bonding performance (11.2 MPa) than the commercial reactive polyurethane hot melt adhesive (PUR-Ausbond 3550) and can reach 10.2 MPa after three times break as thermoplastic polyurethane hot melt adhesive (TPU-XJU83), due to the higher cross-linked density and the thermal reversibility of DA adducts. This confirmed that DAPU combined the merits of the two kinds of polyurethane hot melt adhesives successfully without involving solvents.

Fabrication of photothermal responsive dual-chamber microcapsules for self-healing epoxy anticorrosion coatings

It has been urgent that timely repair of microdamage generated during long-term service of metal insulation coatings. Hereby, we developed a novel self-healing dual-chamber microcapsule with particle size about 5 μm, in which furfuryl amine modified polystyrene-acrylic acid (PSAF) as shell material and photosensitizer Carbon dots (CDs) as Pickering emulsifier. The synthesized materials were characterized analytically, FTIR and DSC demonstrated the simultaneously existence of healing agent and curing agent in the resultant dual-chamber microcapsule. Experiments also showed microcapsules exhibited satisfying storage stability more than 20 d at room temperature as well as thermogenesis effect that allowing temperature of epoxy composite materials raised to 50 °C in 60s and fractures to be effectively minimized in time. The scratch tensile measurement results demonstrated that epoxy resin composites incorporated with 2 wt% microcapsules exhibited the optimal strength self-healing efficiency, modulus, toughness and anti-fatigue performance. Furthermore, surface characterization and EIS analysis also confirmed the long-lasting healing effect of EP/MC2% complex coating with outstanding corrosion resistance. Therefore, the photothermal responsive dual-chamber microcapsule designed in this work has application as self-healing material especially epoxy anti-corrosion coating.

Coordinated metal complexes with curcumin Schiff base: Synthesis, investigation, antibacterial screening, antioxidant studies, molecular docking and density function theory calculations

Condensation of curcumin with furfuryl amine led to the synthesis of H2L Schiff base in a 1:1 Molar ratio. Subsequently, complexes of this Schiff base with several transition metal ions were prepared also in one‐to‐one molar ratio. Multiple characterization techniques were employed to identify the structure of all compounds. Infrared, UV, proton magnetic resonance spectroscopic tests, elemental analysis, mass spectrometry, thermal analysis, molar conductivity, and density function theory (DFT) calculations were utilized to gain a comprehensive understanding of their structures. Except for the nickel (II) complex, which exhibits non‐electrolyte behavior, all complexes were found to exhibit electrolytic behavior based on molar conductivity studies. Additionally, thermogravimetric analysis was employed to learn more about the complexes' thermal breakdown and the Schiff base ligand's thermal behavior. From DFT studies, some parameters were obtained as bond angles and lengths, chemical hardness, softness, energy levels of highest occupied molecular orbital and lowest unoccupied molecular orbital, electrophilic index, dipole moment, electronegativity, and other variables. Against one or more bacterial species, it was discovered that the antibacterial activity of the metal complexes was superior to that of the free Schiff base. Furthermore, the complexes exhibited notable antioxidant activity according to the results obtained using DPPH scavenging. Overall, a detailed characterization of the synthesized compounds was performed, revealing their structural features, functional properties, and potential applications. Lastly, research on molecular docking was investigated toward all compounds against 3C1L antioxidant protein receptor.

Preparation and Characterization of Conductive/Self-Healing Resin Nanocomposites Based on Tetrafunctional Furan-Functionalized Aniline Trimer Modified Graphene.

The nanocomposites with reversible cross-linking covalent bonds were prepared by reacting furfurylamine (FA)-modified diglycidyl ether of bisphenol A (DGEBA) and furfuryl-functionalized aniline trimer-modified graphene (TFAT-G) with bismaleimide (BMI) via the Diels-Alder (DA) reaction. The successful synthesis of the TFAT modifier is confirmed by nuclear magnetic resonance (NMR) hydrogen spectroscopy and IR spectroscopy tests. The structure and properties of TFAT-G epoxy nanocomposites are characterized by scanning electron microscopy (SEM), differential scanning calorimeter (DSC), tensile, and resistivity. The results show that TFAT-G was uniformly dispersed in the resin, and 1 wt% TFAT-G composites increased to 233% for tensile strength, 63% for elongation at break, 66% for modulus, and 7.8 °C for Tg. In addition, the addition of unmodified graphene degrades the mechanical properties of the composite. Overall, the graphene/self-healing resin nanocomposites have both good self-healing function and electrical conductivity by adding 1 wt% modified graphene; this allows for the maintenance of the original 83% strength and 89% electrical conductivity after one cycle of heating repair.

External [1 1 1] facets on nanorod gamma alumina boosts catalytic reductive amination of carbonyl compound to primary amine

Hydrogen spillover had played a significant role in catalytic processes involving reducible oxide supported metal catalyst and hydrogen molecule. Herein, crystal plane regulative hydrogen spillover strategy for the effective reductive amination on Ni/Al2O3 was developed. A rod-like alumina supported Ni catalyst with primarily external (111) facets was prepared. In the presence of NH3 and H2, Ni/Al2O3 (111) exhibited a turnover number of 30.4 h−1, which was 136-fold higher than that of Ni/Al2O3 (110) in the reductive amination of furfural to furfuryl amine. For the Ni/Al2O3 (111) catalyst, Al2O3 (111) facets exhibited strong Lewis acidity, resulting in an enhanced H affinity of Al2O3 (111) and a positively charged of Ni through electronic interaction. It was revealed that strong H affinity of Al2O3 (111) and positively charged Ni sites significantly promoted hydrogen migration from Ni surface to Al2O3 (111) facets, which effectively prevented the Ni sites from hydrogen poisoning and enhanced the adsorption and activation of NH3 and intermediates for reductive amination. Consequently, the activation energy of Schiff base reductive ammonolysis was obviously reduced, resulting in high inherent activity for furfural reductive amination to furfuryl amine. This work developed a new strategy for high efficiency reductive amination catalyst in terms of hydrogen spillover effect.

Modulation of coordination environment on atomically dispersed Ir catalysts for highly-efficient reductive amination

The modulation of coordination environment on active metal atom as well as the cognition of selective-structure relationship have drawn widespread attention in heterogeneous hydrogenation reactions, but remain a big challenge. Here, we report 1 % Ir species supported on NiO nanosheet via a reduction process in hydrogen at various temperatures (donated as 1 %Ir/NiO-160, 1 %Ir/NiO-180 and 1 %Ir/NiO-200). Notably, the optimal catalyst 1 %Ir/NiO-180 exhibits an unexceptionable catalytic behavior (yield > 99 %) in furfural reductive amination reaction. A conjoint investigation based on AC-HAADF-STEM, XAFS and in situ CO-IR confirms the most abundant Ir − Ni coordination in 1 %Ir/NiO-180 catalyst, as well as mainly Ir − O coordination and Ir − Ir coordination in 1 %Ir/NiO-160 and 1 %Ir/NiO-200, respectively. Studies on structure-selective relationship based on in situ experiments and theoretical calculations further uncover that the Ir-Ni interfacial sites as intrinsic active centers simultaneously promote the adsorption of reaction intermediates (N-furfurylidenefurfurylamine) and the dissociation of NH3. Therefore, this process effectively promotes the reductive amination of reaction intermediate, leading to the production of furfurylamine (FAM) with a rather highly catalytic selectivity. This work provides an effective strategy for the modulation of coordinationenvironment on active metal atom, which is constructive for the design and optimization of catalyst structure in the heterogeneous catalysis.

Green composites from vanillin‐based benzoxazine: Modified almond shell particles, curing behavior, thermal stability, mechanical properties, and stress analysis

AbstractBy adhering to green chemistry principles, unique and enhanced benzoxazine composite is made from renewable vanillin and furfuryl amine. The bio‐benzoxazine poly(V‐BZF) structure was confirmed by1H NMR and Fourier‐transform infrared spectroscopy spectroscopy. Enhanced composites were developed successfully by blending different chemical‐treated almond shell particles with poly(V‐BZF). Differential scanning calorimetry results reveal that novel benzoxazine's curing temperature was low and slightly reduced by incorporating chemically treated fillers. The lowest polymerizing temperature was recorded as 215°C for the blend of alkali‐treated particles. Thermogravimetric analysis demonstrates that composites exhibited superior thermal characteristics, and chemical treatment positively impacts filler material. The limiting oxygen index value classifies poly(V‐BZF) composites as flame‐retardant and extinguishing. Approximately a 47.56% increase in tensile strength and a 28.9% increase in modulus were recorded with the incorporation of silane‐treated filler. Flexural tests demonstrated that composites with silane‐treated particles showed maximum flexural strength of 101.5 MPa and a modulus of 4112.6 MPa. The impact strength of composites increased to 73.3%, expanding benzoxazine's manufacturing applications. In addition, the specimen was designed to have composite properties and stress analysis was performed in two Multiphysics software packages. In all, this work confirms that adopting environmentally‐friendly methodologies and surface modification of filler can yield superior composites.

Chemobiocatalytic transfromation of biomass into furfurylamine with mixed amine donor in an eco-friendly medium

Biobased furfurylamine (FAM) is a versatile platform molecule for producing additives, pharmaceuticals, and pesticides. Recombinant E. coli HNND-AlaDH was created by co-expressing L-alanine dehydrogenase (AlaDH) and mutated Aspergillus terreus ω-transaminase (HNND), aiming to convert furfural (FUR) into FAM using inexpensive L-alanine and isopropylamine as mixed amine donors. In ChCl:FA:OA (10 wt%), pineapple peel, bagasse, barley shell, peanut shell, and corn stalk could be efficiently transformed into FUR under 170 °C for 10 min. Pineapple peel produced a high titer of FUR (183.3 mM). Additionally, the viscosity, surface tension and polarity of ChCl:FA:OA were explored. The biomass-derived FUR was fully transformed to FAM by HNND-AlaDH with amine donor (1:1:1 of L-Ala/isopropylamine/FUR mol/mol/mol) within 300 min. Accordingly, the FAM productivity was 0.58 g/(g xylan in pineapple peel). This chemobiocatalytic strategy established through the combination of chemocatalysis and biocatalysis could be applied to convert renewable biomass into valuable organic amines.

Bisphenol A Diglycidyl Ether-Primary Amine Cooligomer-poly(ε-caprolactone) Networks: Synthesis and Characterization.

In this work, the preparation and systematic investigation of cross-linked polyurethane-epoxy (PU-EP) polymer systems are reported. The PU-EP polymers were prepared using a reaction of isocyanate (NCO)-terminated PU-prepolymer with diglycidyl ether of bisphenol A (DGEBA)-amine cooligomer. The oligomerization of DGEBA was carried out by adding furfurylamine (FA) or ethanolamine (EA), resulting in DGEBA-amine cooligomers. For the synthesis of NCO-terminated PU-prepolymer, poly(ε-caprolactone)diol (PCD) (Mn = 2 kg/mol) and 1,6-hexamethylene diisocyanate (HDI) were used. The cross-linking was achieved by adding DGEBA-amine cooligomer to PU-prepolymer, in which the obtained urethane bonds, due to the presence of free hydroxil groups in the activated DGEBA, served as netpoints. During cross-linking, ethanolamine provides an additional free hydroxyl group for the formation of a new urethane bond, while furfurylamine can serve as a thermoreversible coupling element (e.g., Diels-Alder adduct). The PU-EP networks were characterized using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA) and scanning electron microscopy (SEM). The DMA curves of some PU-EPs (depending on the compositions and the synthetic method) revealed a plateau-like region above the melting temperature (Tm) of PCD, confirming the presence of a cross-linked structure. This property resulted in a shape memory (SM) behavior for these samples, which can be fine-tuned in the presence of furfurylamine through the formation of additional thermoreversible bonds (e.g., Diels-Alder adduct).

Laccases from Pleurotus ostreatus applied to the oxidation of furfuryl alcohol for the synthesis of key compounds for polymer industry.

Laccases are oxidative enzymes with high synthetic potential. In this work, we prove their value in biocatalysis through the green and selective oxidation of furfuryl alcohol into furfural with the aid of mediators. The influence of different parameters such as pH, enzyme/mediator composition, buffer type, cosolvent tolerance and reaction times were deeply investigated. Under the optimal conditions, 20 mol% of TEMPO as mediator, and 5.8 U mL-1 of laccases POXC and POXA1b from Pleurotus ostreatus allowed to achieve quantitative production of furfural after 16 h. POXC laccase stood out for its ability to catalyze the reaction at pH 6.5, meanwhile POXA1b highlighted for its high stability. Furfural conversions reached excellent values (95%) after 72 h using only 5 mol% of TEMPO at 100 mM. Furthermore, furfuryl alcohol bioamination was successfully achieved employing the amine transaminase from Chromobacterium violaceum, providing furfuryl amine, a key compound for polymer industry, through a one-pot sequential approach.

Evaluating the Microheterogeneous Distribution of Photochemically Generated Singlet Oxygen Using Furfuryl Amine.

Singlet oxygen (1O2) is an important reactive species in natural waters produced during photolysis of dissolved organic matter (DOM). Prior studies have demonstrated that 1O2 exhibits a microheterogeneous distribution, with [1O2] in the interior of DOM macromolecules ∼30 to 1000-fold greater than in bulk solution. The [1O2] profile for DOM-containing solutions has been determined mainly by the use of hydrophobic probes, which are not commercially available. In this study, we employed a dual-probe method combining the widely used hydrophilic 1O2 probe furfuryl alcohol (FFA) and its structural analogue furfuryl amine (FFAm). FFAm exists mainly as a cation at pH <9 and was therefore hypothesized to have an enhanced local concentration in the near-DOM phase, whereas FFA will be distributed homogeneously. The probe pair was used to quantify apparent [1O2] in DOM samples from different isolation procedures (humic acid, fulvic acid, reverse osmosis) and diverse origins (aquatic and terrestrial) as a function of pH and ionic strength, and all samples studied exhibited enhanced reactivity of FFAm relative to FFA, especially at pH 7 and 8. To quantify the spatial distribution of [1O2], we combined electrostatic models with Latch and McNeill's three-phase distribution model. Modeling results for Suwannee River humic acid (SRHA) yield a surface [1O2] of ∼60 pM, which is ∼96-fold higher than the aqueous-phase [1O2] measured with FFA. This value is in agreement with prior reports that determined 1-3 orders of magnitude higher [1O2] in the DOM phase compared to bulk solution. Overall, this work expands the knowledge base of DOM microheterogeneous photochemistry by showing that diverse DOM isolates exhibit this phenomenon. In addition, the dual-probe approach and electrostatic modeling offer a new way to gain mechanistic insight into the spatial distribution of 1O2 and potentially other photochemically produced reactive intermediates.

Reductive amination of furfural and furfurylamine with methoxides and MIL-53-NH2(Al)-derived Ru catalyst

BackgroundDifurfurylamine (DiFAM)22DiFAM: difurfurylamine. is a valuable chemical used in pharmaceuticals or polymers, but an efficient synthesis is rarely reported. One such method involves the imination of furfural (FAL)33FAL: furfural. and furfurylamine (FAM)44FAM: furfurylamine. to form difurfurylimine (DiFIM),55DiFIM: difurfurylimine. followed by the hydrogenation of DiFIM to produce DiFAM. This process can be carried out effectively using Ru nanoparticles and borohydrides as catalyst and reducing agent, respectively. Understanding the mechanism of this reaction is crucial for designing similar systems in the future. MethodsThe materials Ru@Al2O3 and Ru/γ-Al2O3 were synthesized via in situ synthesis and impregnation, respectively. Characterization was then performed to verify the physicochemical properties of the materials. The catalytic reaction was carried out in an 80 °C oil bath with stirring for 1 h. Simulations were performed using density functional theory (DFT).66DFT: density functional theory. Significant findingsRu@Al2O3 obtained from MIL-53-NH2(Ru, Al) demonstrated a higher dispersion of Ru NPs due to their interaction with the –NH2 ligands on MIL-53-NH2(Al). Moreover, DFT calculations predicted that the methanolysis products of borohydrides could reduce the activation energy of the reaction by forming a stable transition state. These factors combined to yield an impressive ca. 92% of DiFAM and provide new insights for designing hydrogenation systems.

Sustainable Chitosan/Polybenzoxazine Films: Synergistically Improved Thermal, Mechanical, and Antimicrobial Properties.

Polybenzoxazines (Pbzs) are considered as an advanced class of thermosetting phenolic resins as they overcome the shortcomings associated with novolac and resole type phenolic resins. Several advantages of these materials include curing without the use of catalysts, release of non-toxic by-products during curing, molecular design flexibility, near-zero shrinkage of the cured materials, low water absorption and so on. In spite of all these advantages, the brittleness of Pbz is a knotty problem that could be solved by blending with other polymers. Chitosan (Ch), has been extensively investigated in this context, but its thermal and mechanical properties rule out its practical applications. The purpose of this work is to fabricate an entirely bio-based Pbz films by blending chitosan with benzoxazine (Bzo), which is synthesized from curcumin and furfuryl amine (curcumin-furfurylamine-based Bzo, C-fu), by making use of a benign Schiff base chemistry. FT-IR and 1H-NMR spectroscopy were used to confirm the structure of C-fu. The impact of chitosan on benzoxazine polymerization was examined using FT-IR and DSC analyses. Further evidence for synergistic interactions was provided by DSC, SEM, TGA, and tensile testing. By incorporating C-fu into Ch, Ch-grafted-poly(C-fu) films were obtained with enhanced chemical resistance and tensile strength. The bio-based polymer films produced inhibited the growth of Staphylococcus aureus and Escherichia coli, by reversible labile linkages, expanding Ch galleries, and releasing phenolic species, which was 125 times stronger than bare Ch. In addition, synthesized polybenzoxazine films [Ch/Poly(C-fu)] showed significant dose-dependent antibiofilm activity against S. aureus and E. coli as determined by confirmed by confocal laser scanning microscopy (CLSM). This study suggests that bio-based Ch-graft-polymer material provide improved anti-bacterial property and characteristics that may be considered as a possibility in the near future for wound healing and implant applications.

Active metal dependent side reactions for the reductive amination of furfural

In addition to the main reaction, understanding the structure-activity relationship in the side reactions is another important goal for catalysis science. In this work, the catalytic activities and selectivities of various active metals were studied in the reductive amination of furfural (FAL). Compared with Co- and Ni-based catalysts, the excessive hydrogen of furfurylamine (FAM) was found over Ru-based catalysts at much higher reaction temperature (130 vs. 50 °C). Moreover, the evaluation of FAM hydrogenation undoubtedly substantiated the intimate relationship between H2 reaction pressure and catalytic activity. Combining the theoretical and experimental results, it is clearly verified that the active metal determines the excessive hydrogen of FAM by affecting the competitive adsorption of FAM and H on the active sites.

Sustainable approach for coating production: Room temperature curing of diglycidyl furfuryl amine and itaconic acid with UV-induced thiol-ene surface post-functionalization

In this work, diglycidyl furfuryl amine (DGFA) is synthesized towards the production of a functional coating. With the aim to reduce the energy consumption during processing, a room temperature (RT) curing of the epoxy monomer is performed in presence of bio-based itaconic acid (IA). The RT curing process was demonstrated by means of DSC, rheology, and real-time ATR FTIR and the thermo-mechanical properties were investigated by DMTA. As last step, the properties of the coating surface were modified via an UV-induced thiol-ene reaction between the CC double bonds from itaconic acid moieties and fluorine-based monomers. The surface functionalization was investigated by contact angle measurements and XPS analysis.

Synthesis and characterization of vanillin derived bio-based benzoxazine resin for high temperature application

PurposeThis study aims to synthesize two different benzoxazines (Bz) monomers using bio-based and petroleum-based primary amines, respectively, and they have been compared to study their thermal and mechanical performances.Design/methodology/approachA bio-based bisphenol, Divanillin (DiVa), was formed by reacting two moles of vanillin with one mole of ethylenediamine (EDA) which was then reacted firstly with paraformaldehyde and EDA to form the benzoxazine DiVa-EDA-Bz, and secondly with paraformaldehyde and furfuryl amine (FFA) to form the benzoxazine DiVa-FFA-Bz. The molecular structure and thermal properties of the benzoxazines were characterized by fourier transform infrared spectroscopy and nuclear magnetic resonance (1H,13C) spectroscopies, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The benzoxazines were further coated on mild steel panels to evaluate their mechanical properties and chemical resistance.FindingsThe DSC results of DiVa-FFA-Bz showed two exothermic peaks related to crosslinking compared to the one in DiVa-EDA-Bz. The DiVa-FFA-Bz also showed a higher heat of polymerization than DiVa-EDA-Bz. The TGA results showed that DiVa-FFA-Bz exhibited higher thermal stability with a residual char of 54.10% than 43.24% for DiVa-EDA-Bz. The chemical resistance test results showed that DiVa-FFA-Bz showed better chemical resistance and mechanical properties due to its higher crosslinking density.Originality/valueThis study shows the use of bio-based materials, vanillin and FFA, for synthesizing a benzoxazine resin and its application at high temperatures.