Furan Groups Research Articles

Selective hydrogenation of furfural to furfuryl alcohol through hydrogenation spillover over amorphized HA zeolite encapsulated platinum clusters

Design of heterogeneous catalyst to achieve efficient conversion of biomass to high added-value chemicals is still very attractive. Herein, taking industrially important selective hydrogenation of furfural to furfuryl alcohol as an example, the designed amorphized HA zeolite encapsulation of platinum clusters (denoted as Pt@HA) exhibited excellent catalytic selectivity at totally conversion of the reactant furfural, along with good reusability and poison resistance ability. The selected amorphized HA zeolite with very small pore size constrained the reactant furfural to be reacted through hydrogen spillover process at zeolite surface, instead of to be adsorbed and activated onto Pt surface. Resulting from the stronger interaction between nucleophilic oxygen atom of aldehyde group and acid site at HA zeolite surface than that of furan ring group, furfural preferred to adsorb onto Pt@HA surface with the end of aldehyde group rather than the end of furan ring group, thus facilitating the spilled H atom to react with aldehyde group to give desired furfuryl alcohol product exclusively.

Fibrillar Hydrogel Based on Cellulose Nanocrystals Crosslinked via Diels-Alder Reaction: Preparation and pH-Sensitive Release of Benzocaine.

A fibrillar hydrogel was obtained by covalent crosslinking via Diels-Alder reaction of two types of cellulose nanocrystals (CNCs) with furan and maleimide groups. Gelation has been studied at various ratios of components and temperatures in the range from 20 to 60 °C. It was shown that the rheological properties of the hydrogel can be optimized by varying the concentration and ratio of components. Due to the rigid structure of the CNCs, the hydrogel could be formed at a concentration of at least 5 wt%; however, it almost does not swell either in water with pH 5 or 7 or in the HBSS buffer. The introduction of aldehyde groups into the CNCs allows for the conjugation of physiologically active molecules containing primary amino groups due to the formation of imine bonds. Here, we used benzocaine as a model drug for conjugation with CNC hydrogel. The resulting drug-conjugated hydrogel demonstrated the stability of formulation at pH 7 and a pH-sensitive release of benzocaine due to the accelerated hydrolytic cleavage of the imine bond at pH < 7. The developed drug-conjugated hydrogel is promising as wound dressings for local anesthesia.

Influence of maturation and roasting on the quality and chemical composition of new conilon coffee cultivar by chemometrics

Coffee is one of the most consumed beverages worldwide. Espírito Santo is the largest Brazilian producer of conilon coffee, and invested in the creation of new cultivars, such as “Conquista ES8152”, launched in 2019. Therefore, the present study aimed to evaluate the effects of maturation and roasting on the chemical and sensorial composition of the new conilon coffee cultivar “Conquista ES8152”. The coffee was harvested containing 3 different percentages of ripe fruits: 60%, 80%, and 100%, and roasted at 3 different degrees of roasting: light, medium, and dark, to evaluate the moisture and ash content, yield of soluble extract, volatile compound profile, chlorogenic acid and caffeine content, and sensory profile. “Conquista ES8152” coffee has a moisture content between 1.38 and 2.62%; ash between 4.34 and 4.72%; and yield between 30.7 and 35.8%. Sensory scores ranged between 75 and 80 and the majority of volatile compounds belong to the pyrazine, phenol, furan, and pyrrole groups. The content of total chlorogenic acids was drastically reduced by roasting, with values between 2.40 and 9.33%, with 3-caffeoylquinic acid being the majority. Caffeine was not influenced by either maturation or roasting, with values between 2.16 and 2.41%. The volatile compounds furfural, 5-methylfurfural, and 2-ethyl-5-methylpyrazine were positively correlated with the evaluated sensory attributes and 5-methylfurfural was the only one significantly correlated with all attributes. Ethylpyrazine, furfuryl acetate, 1-furfurylpyrrole, 4-ethyl-2-methoxyphenol, and difurfuryl ether were negatively correlated. The stripping did not affect the quality and composition of this new cultivar, however, the roasting caused changes in both the chemical and sensorial profiles, appropriately indicated by the principal component analysis.

Multifunctional, robust, and self‐healable polyurethane coatings cross‐linked by Diels–Alder reaction of calix[4] arenes containing furan groups

AbstractSelf‐healing coatings can restore their performance after inevitable damage and are promising in the industry owing to their longer service life and lower repair cost. The use of Diels–Alder reaction bonds is well‐known to generate thermally self‐healing coatings. In this study, a series of cross‐linked self‐healing polyurethane (PU) coatings were synthesized through Diels–Alder reactions of p‐tert‐butyl calix[4]arene bearing furan groups (C4A‐FA) as a new chain extender and a bismaleimide (BMI) polyether amine as a Diels–Alder cross‐linking agent. Adding C4A‐FA to PUs improves their mechanical properties, thermal stability, and self‐healing ability. Additionally, these modifications can result in the formation of composite networks with PU that exhibit thermoreversibility and self‐healing properties. These changes have led to PUs containing modified calix[4]arene (C4A‐FA) having better properties compared with unmodified calix[4]arene PUs. The properties of prepared coatings were evaluated by Fourier transform infrared spectroscopy, scanning electron microscope, differential scanning calorimetry (DSC), thermogravimetric analyses (TGA), and tensile tests compared with a typical PU sample. The tensile and TGA results show an improvement in the thermal and mechanical properties of the polymers by increasing the C4A‐FA content. By replacing 15% of butandiol (BDO) with C4A‐FA in PU pure, the tensile strength increased from 1.69 to 5.14 MPa. Furthermore, adding diels–alder (DA) bonds enhanced the tensile strength to 10.49 MPa for PU‐C4A15‐DA. According to DSC results, a broad endothermic peak from nearly 80–140°C confirmed the retro‐DA reactions in the synthesized thermoreversible samples. The healing efficiency of the PU‐C4A15‐DA sample was obtained at 92.5% (measured by tensile test), which is the highest value among cross‐linked self‐healing PUs reported in the literature.

Responsive sustainable and biodegradable systems based on Diels-Alder reaction from amylomaize starch

Amylomaize starch (AMS) and poly(butylene adipate-co-terephthalate) (PBAT), a biodegradable and potentially biobased copolyester, were chemically modified to develop a thermally reversible network based on reversible Diels-Alder (DA) reaction between maleimide and furan groups. AMS was esterified with 6-maleimidohexanoyl chloride to obtain AMS–maleimide, as evidenced by FTIR, 1H, 13C and 2D NMR spectroscopies. PBAT was transesterified with 1,4–butanediol to yield PBAT oligomers-based diols (oligoPBAT-diol), to then react with furfuryl isocyanate to obtain oligoPBAT-difuran. The structures of PBAT derivatives were precisely determined by FTIR, 1H, 13C, 31P and 2D NMR spectroscopies and SEC. AMS-maleimide and oligoPBAT-difuran have then undergone a cycloaddition by DA reaction. The final products were analyzed by FTIR spectroscopy and modulated DSC, which showed the occurrence of retro DA. Overall, this study reports the high potential of this thermally responsive smart system to counteract the well-known incompatibility between starch and PBAT within multiphase materials and to develop performing materials for a circular bioeconomy.

Electrically and thermally healable nanocomposites via one-step Diels-Alder reaction on carbon nanotubes

Carbon nanotubes (CNTs) were directly employed as reactive fillers in furan-pendant polyketones via the Diels-Alder (DA) reaction. CNTs and furan groups function as dienophile and diene, respectively, forming a reversible crosslinking network. Here, pristine CNTs not only serve as crosslinking agents, but also improve the thermal and electrical conductivity. The DA covalent linkage was confirmed by IR, TGA, DSC, elemental analysis and dispersion tests. This one-step approach offers a facile route to synthesize reversibly crosslinked thermoset polymer nanocomposites. The rigidity of the nanocomposites could be controlled through the number of furan groups in order to achieve distinct properties. The nanocomposites demonstrated dynamic temperature-dependent behavior due to the retro Diels-Alder reaction. Cyclic tests via rheology showed good reversibility below 120 °C. However, an irreversible increase of modulus was observed at higher temperatures, which is possibly attributed to a side reaction. At filler loadings above 5%, both electrical and thermal self-healing tests showed good results. The Diels-Alder reaction between CNTs and furan-pendant polymers opens up a new possibility of directly employing fillers in the polymer matrix without any prior modifications. It is also possible to use other fillers with diene/dienophile properties in future reversible polymer nanocomposites.

Cholesteric liquid crystalline polysiloxanes containing furan ring with selective reflection – synthesis and properties

ABSTRACT In this paper, first series of liquid crystal polymers (PF) synthesised by hydrosilylation of monomer containing furan group (MA), monomer containing cholesterol group (MB), monomer containing D (+)-camphoric acid group (MC) and monomer containing cyano-group (MD), catalysed by platinum catalyst. Another series of liquid crystal polymers (EF) is synthesised by the Dies-Alder reaction of the former series and cross-linker containing bismaleimide group. The results of Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance(1H NMR) showed the successful preparation of various monomers as well as polymers. The thermal properties of two series were characterised by differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). We observed dramatic colour changes and Grand-jean textures of polymers using polarised optical macroscope (POM). The results of POM and selective reflection showed that both series of polymers are cholesteric liquid crystals. In the latter series, crosslinking by Diels-Alder reaction can make the liquid crystal better oriented, which can maintain their wonderful liquid crystal (LC) texture and selective reflection, and at the same time, it has a certain regulation effect on the appearance of cholesteric Grand-jean blue texture. The results of X-ray diffraction (XRD) further proved the two series of polymers are cholesteric liquid crystals.

Low-Temperature Terpolymerizable Benzoxazine Monomer Bearing Norbornene and Furan Groups: Synthesis, Characterization, Polymerization, and Properties of Its Polymer.

There is an urgency to produce novel high-performance resins to support the rapid development of the aerospace field and the electronic industry. In the present work, we designed and consequently synthesized a benzoxazine monomer (oHPNI-fa) bearing both norbornene and furan groups through the flexible benzoxazine structural design capability. The molecular structure of oHPNI-fa was verified by the combination characterization of nuclear magnetic resonance spectrum, FT-IR technology, and high-resolution mass spectrum. The thermally activated terpolymerization was monitored by in situ FT-IR as well as differential scanning calorimetry (DSC). Moreover, the low-temperature-curing characteristics of oHPNI-fa have also been revealed and discussed in the current study. Furthermore, the curing kinetics of the oHPNI-fa were investigated by the Kissinger and Ozawa methods. The resulting highly cross-linked thermoset based on oHPNI-fa showed excellent thermal stability as well as flame retardancy (Td10 of 425 °C, THR of 4.9 KJg-1). The strategy for molecular design utilized in the current work gives a guide to the development of high-performance resins which can potentially be applied in the aerospace and electronics industries.

MWCNTs filled PCL covalent adaptable networks: Towards reprocessable, self-healing and fast electrically-triggered shape-memory composites

Electrically triggered shape memory polymers efficiency has been proven by numerous studies making them promising novel structural materials for high-end applications. In this field, poly(ε-caprolactone) covalent adaptable networks (PCL-CAN) are particularly appealing since they benefit from excellent shape memory (SM) properties combined with network reconfiguration making easy the design of self-actuated devices of complex shape. Preparation of conducting PCL-CAN networks by melt blending multi-walled carbon nanotubes (MWCNTs) with four-arm star-shaped PCL end-capped with maleimide and furan groups is here investigated. The conventional tensile tester and dynamic mechanical analysis demonstrated the reinforcement of the composite mechanical properties paired with excellent shape memory properties (recovery and fixity ratios about 99%). The simultaneous measurement of the sample resistivity was also integrated to these experiments allowing to follow its evolution during the SM cycles. Rheological measurements highlighted the impact of MWCNTs on the recyclability and self-healing properties of the composite. Electrical triggering of the shape recovery through Joule resistive heating is also deeply studied. The combination of all these properties in the developed material offers unique opportunities to design self-folding multi-materials which is illustrated through the design of smart multi-layered composites. This high-performance composite is especially attractive for reconfiguration of the permanent shape of complex geometry self-deploying devices and their thermal and electrical triggering.

Self-Healing and Flame-Retardant Modifications of Epoxy Resins by the Diels–Alder Release-Delivery Strategy for a High-Efficiency and Green Application

The sustainability of epoxy thermosets (EPs) and EP-based composites is always limited by the evolution of internal microcracks and flammability. Herein, inspired by the drug release-delivery system for disease treatment, these symptoms of EP are solved efficiently by a multifunctional Diels–Alder (DA) release-delivery system. First, this novel system is fabricated by the cyclization reaction between the furan diene-containing phosphorus derivative and the maleimide dienophile. The resultant DA system is linked to the epoxy resin by the grafting reaction, thus ensuring its uniform dispersion. Being faced with the formation of inner microcracks, the maleimide dienophiles were released from the DA adducts under the mediated action of temperature and then were delivered to the targeted microcracks under the chemical potential difference derived from the variation of free volume. Then, the released maleimide molecules re-connect with the furan groups that existed near the microcracks to complete the repairing of the EP matrix. The skeletal structure of the EP was well preserved throughout the restoration process. Satisfactory flexural strength (105.5 MPa) and excellent crack-healing efficiency (104.5%) can be obtained for the modified EP. After three constant strain cycles, the stress retention rate can be readily maintained (more than 75%). In addition, due to the phosphorus–nitrogen synergistic flame-retardant effect from the DA system, not only the limited oxygen index of the DA-modified EP matrix can be improved to 27.5% but the lower peak release rate and lower total heat release are also observed compared with the unmodified EP.

Synthesis, Characterization, Bioactivity Impacts of New Anthranilic Acid Hydrazones Containing Aryl Sulfonate Moiety as Fenamate Isosteres

AbstractIn this study, it was planned to synthesize new members of fenamate isosteres and investigate its effect on some metabolic enzymes such as Acetylcholinesterase, Butyrylcholinesterase, α‐Glucosidase, Carbonic andyhrase I–II. The target compounds were obtained from the reaction of N‐subtituted anthranilic hydrazides with sulfonylated aldehyde derivatives. The structures of the compounds were characterized using Fourier‐transform Infrared, Nuclear Magnetic Resonance, and High‐resolution Mass Spectroscopy. Compounds had potent inhibitory strength with Ki values in the range of 0.23±0.03–7.12±0.41 μM against carbonic anhydrase‐I and 0.13±0.01–6.21±0.52 μM against carbonic anhydrase‐II. Compounds inhibited acetycholinesterase and butyrylcholinesterase with the Ki values in the range of 42.73±15.80 nM–977.52±32.67 nM and 25.84±4.09 nM–261.36±34.05 nM, respectively. All compounds showed potent inhibitory activity against α‐glucosidase enzyme with IC50 value 1.51–23.51 nM, compared to the standard acarbose (64.53 nM). The orientation of binding of the synthesized compounds were further appraised by molecular docking studies, which reflects the importance of sulfonyl, furan, thiophene, and methoxy groups in protein‐ligand interaction. The docking results are complementary with the Ki values of compounds while the interaction pattern of the current compounds clearly indicates their structure‐activity relationship.

NIR Light‐Mediated Mitochondrial RNA Modification for Cancer RNA Interference Therapeutics

AbstractMitochondrial RNA (mtRNA) plays a critical role in synthesis of mitochondrial proteins. Interfering mtRNA is a highly effective way to induce cell apoptosis. Herein, we report a near‐infrared (NIR) light‐mediated mitochondrial RNA modification approach for long‐term imaging and effective suppression of tumors. A tumor‐targetable NIR fluorescent probe f‐CRI consisting of a cyclic RGD peptide, a NIR fluorophore IR780, and a singlet oxygen (1O2)‐labile furan group for RNA modification was rationally designed and synthesized. This probe was demonstrated to dominantly accumulate in cellular mitochondria and could be covalently conjugated onto mtRNA upon 808 nm irradiation resulting in prolonged retention in tumors. More notably, this covalent modification of mtRNA by f‐CRI could perturb the function of mitochondria leading to remarkable tumor suppression. We thus envision that our current approach would offer a potential approach for cancer RNA interference therapeutics.

NIR Light-Mediated Mitochondrial RNA Modification for Cancer RNA Interference Therapeutics.

Mitochondrial RNA (mtRNA) plays a critical role in synthesis of mitochondrial proteins. Interfering mtRNA is a highly effective way to induce cell apoptosis. Herein, we report a near-infrared (NIR) light-mediated mitochondrial RNA modification approach for long-term imaging and effective suppression of tumors. A tumor-targetable NIR fluorescent probe f-CRI consisting of a cyclic RGD peptide, a NIR fluorophore IR780, and a singlet oxygen (1O2)-labile furan group for RNA modification was rationally designed and synthesized. This probe was demonstrated to dominantly accumulate in cellular mitochondria and could be covalently conjugated onto mtRNA upon 808 nm irradiation resulting in prolonged retention in tumors. More notably, thie covalent modification of mtRNA by f-CRI could perturb the function of mitochondria leading to remarkable tumor suppression. We thus envision that our current approach would offer a potential approach for cancer RNA interference therapeutics.

Beyond Diels-Alder: Domino reactions in furan-maleimide click networks

The furan-maleimide Diels-Alder chemistry has emerged as an important tool to design thermo-reversible click networks. This not only preserves the strong and robust properties of thermo-sets and rubbers, but also makes it possible to cleave crosslinks at non-degradative temperatures, or in other words to recycle them. In this work a new reaction is reported in furan-maleimide click networks, which is the Double-Diels-Alder reaction (DDA), also known as domino Diels-Alder. This forms extra linkages between Diels-Alder adducts and non-reacted furan groups and evidently leads to stronger materials, but also prevents efficient thermal (re)cycling. This work shows with nuclear magnetic resonance (NMR) characterization, differential scanning calorimetry (DSC) and rheology that the DDA reaction can occur both in intramolecular and intermolecular fashion, but also that it exhibits reversibility just like the regular Diels-Alder reaction. This reaction can be easily overlooked creating what at first sight might be inexplicable reactivity when analyzing the properties of furan-maleimide click networks.

Hyaluronic-acid based redox-responsive hydrogels using the Diels-Alder reaction for on-demand release of biomacromolecules

Hydrogels are crosslinked, three-dimensional hydrophilic polymeric networks which possess similarity in structure to human soft tissue, and thus have found a great number of applications as biomaterials. Hydrogels can also act as depot for therapeutic cargo, where small molecule drugs to biomolecules can be encapsulated within their porous structure. The aim of this work is to fabricate redox-responsive hydrogels that can dissolve and release biomacromolecules upon exposure to a reducing environment. In particular, hyaluronic acid (HA), was modified with electron-rich furan groups to yield hydrogels through the Diels-Alder (DA) reaction with a maleimide group containing redox-responsive polyethylene glycol (PEG) based crosslinker. Redox-responsive hydrogels were obtained with high conversions (87–95%) at 37 °C, in a catalyst-free fashion. The stimuli-responsive degradation of hydrogels could be tuned by varying the amount of crosslinker. To examine the passive and on-demand delivery of biomacromolecules, a model protein, fluorescein isothiocyanate conjugated bovine serum albumin (FITC-BSA), was encapsulated within the hydrogels. While a sustained passive release was observed in PBS, a rapid on-demand release was obtained upon exposure to the reducing agent 1,4-dithiothreitol (DTT). Furthermore, the complete dissolution of the hydrogel was accomplished upon exposure to a solution containing the reducing agent.

In SilicoStudy of Thiourea Derivatives as Potential Epidermal Growth Factor Receptor Inhibitors

Over the years, the escalation of cancer cases has been linked to the resistance, less selectivity, and toxicity of available anticancer drugs to normal cells. Therefore, continuous efforts are necessary to find new anticancer drugs with high selectivity of epidermal growth factor receptor tyrosine kinase (EGFR-TK) as a therapeutic target. The EGFR-TK protein has a crucial role in cell proliferation and cancer progression. With about 30% of cancer cases involved with the protein, it has piqued the interest as a therapeutic target. The potential of theoretically designed thiourea derivatives as anticancer agents in this report was evaluated against EGFR-TK via in silico techniques, including molecular docking (AutoDock Vina), molecular dynamics simulations (GROMACS), pharmacokinetics, and drug-likeness properties (SwissADME and Molinspiration). New hybrid molecules of the thiourea derivative moiety were designed in this study based on the fragment-based drug discovery and linked with diverse pharmacophoric fragments with reported anticancer potential ([Formula: see text]) and the modification of the methyl position on phenyl ring ([Formula: see text]). These fragments include pyridine, thiophene, furan, pyrrole and styrene groups. Out of 15 compounds, compound 13 displayed the most potent inhibitory activity, with the lowest binding affinity in docking of [Formula: see text]8.7 kcal/mol compared to the positive control erlotinib of [Formula: see text]6.7 kcal/mol. Our molecular dynamics (MD) simulations revealed that molecule 13, comprising styrene and 2-methylphenyl substituents on [Formula: see text] and [Formula: see text], respectively, showed adequate compactness, uniqueness and satisfactory stability. Subsequently, the absorption, distribution, metabolism, excretion and toxicity (ADMET) properties and drug-likeness properties also indicate that this theoretically designed inhibitor ( 13) is less toxic and contains high druggable properties. Thus, compound 13 could be promising against EGFR-TK.

Poly(thioether) grafted Ti3C2Tx MXenes: New dielectric elastomer nanocomposites with high area strain at low driving voltage

Dielectric elastomers (DEs) with high actuated strains at low electric fields have been a great challenge over the past few decades. In this work, we report the preparation of poly(thioether) grafted Ti3C2Tx MXene DE nanocomposites (MXeneK-FGE-BMI) with high area strain at low driving voltage (17.1 %@11.9 V/μm) by two steps: the pretreated MXene (MXeneK) initiated decarboxylative ring-opening polymerization (ROP) of furfuryl glycidyl ether (FGE) and carbonyl sulfide (COS), followed by the Diels-Alder (DA) crossslinking reaction between furan groups and bismaleimide (BMI). The grafting of poly(thioether) chains onto the MXeneK surfaces enables MXeneK well dispersed in the matrix, leading to the significant decrease of dielectric loss (tan δ, below 0.04@103Hz). Low content of MXeneK (below 1.0 wt%) resulted in high ε’ (∼12.3@103Hz) and low elastic modulus (Y, below 0.5 MPa). Therefore, the resultant DE nanocomposite present a high area strain of 17.1 % at a driving voltage of 11.9 V/μm, superior to the previous reports (0.7 %∼10 %@12 V/μm). This work provides a facile strategy to prepare DE nanocomposites with excellent electromechanical performances at low driving voltage.

A highly thermally stable benzoxazine resin derived from norbornene and natural renewable tyramine and furfurylamine

Highly thermally stable polymeric materials synthesized from renewable resources are highly desirable in many high-performance fields due to the sustainable development of human beings. Herein, a new norbornene-containing monobenzoxazine thermosetting resin (HPTM-fa) exhibiting very high thermal stability has been prepared using natural bio-resourced tyramine and furfurylamine as starting materials. The structural details of HPTM-fa were characterized by FT-IR, NMR as well as high-resolution mass spectroscopies. The polymerization behaviors of cross-linkable norbornene, oxazine ring, and furan groups in HPTM-fa were investigated by DSC and in situ FT-IR analyses. In addition, the polybenzoxazine thermoset derived from this newly obtained bio-based mono-benzoxazine resin showed very high thermal stability with a Td5 of 413 °C and a glass transition temperature of 290 °C. The outstanding performance of thermoset based on HPTM-fa evidences its potential applications in the design of highly thermally stable polymeric materials.

The effect of the lignocellulosic filler on the reduction of fire hazard of styrene-butadiene rubber composites, including the reduction of smoke, PCDD/F, PAH emissions and toxicity during its thermal decomposition

Carbon black commonly found in elastomeric composites is the main precursor of smoke formed during thermal decomposition and combustion of these materials. It has been proven that soot particles suspended in the air, absorbing carcinogenic, mutagenic and teratogenic, organic compounds from the groups of dioxins, furans and polyaromatic hydrocarbons, penetrating into living organisms through the respiratory tract, pose a serious threat to human health and life. Therefore, it has been proved in this paper, that partial replacement of carbon black with a natural lignocellulosic filler, also in synergetic system with non-halogen flame retardants, not only reduces the flammability of the obtained composites, but also significantly reduces their smoke formation, PCDD/Fs and PAHs emissions, as well as the toxicity of gaseous inorganic decomposition products expressed by a toxicometric index taking into account the emissions of CO, CO2, SO2, NO2, HCl and HCN. In addition, the use of natural fillers in elastomeric composites perfectly fits the European regulations regarding the development of reusable or recyclable materials and reducing the cost of their production through the use of cheap renewable raw materials.Flammability and smoke density of studied composites were determined in accordance with European standards with the use of cone calorimeter and smoke density chamber.PCDD/F and PAH were determined with the use of GC-MS-MS technique. Toxicometric index was determined with the use of FB-FTIR technique (fluidised bed reactor and the infrared spectrum analysis).

Insight into the Compositional Features of Organic Matter in Xilinguole Lignite through Two Mass Spectrometers.

Ethanolysis of lignite is an effective approach for converting organic matter of lignite to liquid coal derivatives. Xilinguole lignite (XL) was reacted with ethanol at 320 °C. Then ethanol and isometric carbon disulfide/acetone mixture were used to extract the reaction mixture in a modified Soxhlet extractor to afford extractable portion 1 (EP1) and extractable portion 2 (EP2), respectively. According to analysis of EP1 with a gas chromatography/mass spectrometer, phenolic compounds made up more than 33% of the compounds detected. This could be ascribed to the ethanolysis of XL; that is, ethanol could selectively break the Calkyl-O bonds in lignite, producing more phenolic compounds. Furthermore, a quadrupole Orbitrap mass spectrometer equipped with an atmospheric pressure chemical ionization source was used for comprehensive analysis of the compositional features of EP1. The analysis indicated that O1-3, N1O0-2, and N2S1O3-6 were predominant class species in EP1. Nitrogen atoms in NO-containing organic compounds may exist in the form of pyridine or amidogen, while oxygen atoms primarily exist in furan, alkoxy, carbonyl, and ester groups. In addition, possible chemical structures of NO-containing organic compounds were speculated.