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A facile synthetic approach to diazepine and/or benzimidazole derivatives has been developed through the reaction of enamine [N1-(1-phenylethenyl)benzene-1,2-diamine] obtained from o-phenylenediamine and acetophenone. Its reaction with isophthaloyl chloride produced bis(1,5-benzodiazepinyl)benzene derivative via cyclization involving the nucleophilic enamino carbon atom, whereas the cyclocondensation with diethyl succinate occurred at the nucleophilic nitrogen atom to give bis-benzimidazole derivative. Depending on the conditions, the cyclization with carbon disulfide in DMSO afforded tricyclic 4-phenylimidazo[4,5,1-hi]indole-2(1H)-thione, while 4-phenyl-1,3-dihydro-2H-1,5-benzodiazepine-2-thione was formed in the presence of pyridine. Cyclocondensation of o-phenylenediamine with two equivalents of acetophenone in acid medium produced 3-phenyl-1-(1-phenylethenyl)-1,4-dihydroquinoxaline. N-(2-Aminophenyl)thiourea obtained from o-phenylenediamine and ammonium thiocyanate reacted with chloroacetyl chloride, diethyl malonate, carbon disulfide, and sodium nitrite in aqueous HCl to afford benzimidazole, thiadiazolobenzimidazole, and benzotriazole derivatives.

The reaction of alkyl 2-(bromozinc)acylates, obtained from ethyl bromoacetate (or butyl 2-bromobutanoate, or butyl 2-bromo-2-methylpropanoate) under the action of zinc, with N-chloro- or N-bromodiethylamine in tetrahydrofuran at 20–25°C under argon for 2 h resulted in the formation of diethyl succinate (or dibutyl 2,3-diethyl succinate, or dibutyl tetramethyl succinate) and diethylamine instead of the expected products of the nucleophilic substitution of the halogen with the 2-alkoxycarbonylalkyl residue. An anion-radical reaction mechanism was proposed.

In the current study, carboxylic acid-based deep eutectic solvent including a hydrogen bond donor (acetic acid) and a hydrogen bond acceptor (menthol) has been synthesized and applied for the removal of diclofenac from its aqueous medium. Physical properties (acidity, density, viscosity, and refractive index) of the synthesized liquids were determined quantitatively. The designed deep eutectic solvent was also characterized by Fourier transform infrared spectroscopy method. The removal of diclofenac has been reached to ≈ 80% through the proposed solvent system of reactive liquid extraction. Initial DIC concentration (9.87, 20.29, 29.44, 38.83, and 48.28 mg L−1), deep eutectic solvent level (0, 20, 40, 60, and 80%) in diethyl succinate, and the temperature (293.15, 303.15, 313.15, and 323.15 K) have affected the extraction efficiency. Ionic concentration in extraction medium leads to drop the diclofenac removal. Effects of fluorine and chlorine on the removal of diclofenac have been also investigated. Thermodynamics of the diclofenac transfer from aqueous environment to organic phase containing deep eutectic solvent has been found to be a spontaneous and endothermic process, which is incentivized by entropy.

Green chemistry era forces scientists to develop and apply new media in recovery of high-added value materials. It is interesting to utilize deep eutectic liquids (DELs), which have advantages of biodegradability and very low toxicity and ease of use, in separating these fine materials from a complex environment. DELs have been specially designed and used for the extraction of recovery of acetic acid (AA) from its aqueous solutions. Two DELs containing the same hydrogen bond donor-HBD (glycerol) and two different hydrogen bond acceptor-HBA (a quaternary ammonium salt and an amine-based) have been designed with a molar ratio of 1:2. The tailor-designed extractants were diluted with diethyl adipate (DEA), diethyl malonate (DEM), and diethyl succinate (DES), respectively. Extraction efficiency of the diluents has been increased more than 4 times. To compare the results with that of the ionic liquid (IL), 1-hexyl-3-methylimidazolium bromide has been used in the same organic solvents. Efficiencies of the DELs have surpassed 1.4 to 4 times over the IL.

Several putative lipase genes from the genome of the yeast Blastobotrys (Arxula) raffinosifermentans (adeninivorans) LS3 were overexpressed in the yeast itself and screened for the desymmetrization of the dicarboxylic acid diester diethyl adipate (DEA) into the monoester monoethyl adipate (MEA). MEA can serve as a monomeric spacer group for functional polymers used in medical chemistry and dental applications. The selected lipase Alip2-c6hp was intracellularly located. After overexpression of the corresponding gene, it was purified and biochemically characterized using p-nitrophenyl butyrate as the substrate for standard activity tests. In fed-batch cultivation with constructed yeast strain B. raffinosifermentans G1212/YRC102-Alip2-c6h for large scale production of the Alip2-c6hp biocatalyst enzyme activities up to 674 U L−1 were reached. Several tested diesters were hydrolyzed selectively to monoesters. Under optimized conditions, the purified enzyme Alip2p-c6h converted 96 % of the substrate DEA to MEA within 30 min incubation, whereby only 1.6 % of the unwanted side-product adipic acid (AA) was formed. At room temperature the dicarboxylic acid esters diethyl malonate (DEM), diethyl succinate (DES), dimethyl adipate (DMA) and dimethyl suberate (DMSub) were completely hydrolyzed to their corresponding monoesters. A high yield of 87 % and 25 % could also be achieved with the dioldiesters 1,4-diacetoxybutane (DAB) and diacetoxyhexane (DAH). In conclusion the potential of the lipase Alip2-c6hp expressed in B. raffinosifermentans is very promising for selective hydrolysis of DEA to MEA as well as for the production of other monoesters.

The centrosymmetric title compound, C22H36N2O2, was prepared in five steps from diethyl succinate. The dipropylamino groups are almost orthogonal to the central phenylenedimethanol ring [dihedral angle = 87.62 (9)°]. In the crystal, the molecules are connected by O—H...N hydrogen bonds, forming (101) layers separated by the propyl chains.

The study was carried out to analyse volatile compounds (VOCs) associated to sensory changes during the storage of traditional sorghum beer at ambient temperature and 4 °C. Tchapalo samples were collected and stored at ambient temperature (27–30 °C) for four days and at 4 °C for six days. Volatile and sensory changes were monitored during the storage period. VOCs were extracted and detected using HS-GC/FID and SPME-GC/MS. These methods allowed to identify 68 volatile compounds. The use of SPME fiber permitted to obtain 63 volatile compounds, while simple headspace (HS) was able to extract only 10 compounds. The proportions of isoamyl alcohol, phenylethyl alcohol, ethyl lactate, isoamyl acetate, ethyl hexanoate, ethyl DL-leucate, ethanol, diethyl succinate, phenethyl acetate and benzene acetaldehyde observed significant variation during the storage at ambient temperature. For Tchapalo stored at 4 °C, the proportions of ethanol, ethyl lactate, isoamyl acetate, ethyl hexanoate, ethyl octanoate and phenylethyl alcohol presented significant variation. Principal component analysis based on quantitative changes of these volatile compounds showed three groups among Tchapalo samples which reflected to the differences observed during the sensory evaluations.

Considering the rising demand to diminish energy consumption and CO2 emissions, the biobased segmented block copolymer, poly(butylene succinate-co-dilinoleic succinate) (PBS-DLS) with 70:30 (wt %) ratio of hard to soft segments was obtain using Candida antarctica lipase B (CAL-B) as a biocatalyst. Throughout two-step synthesis in diphenyl ether, biobased diethyl succinate was polymerized with renewable 1,4–butanediol and dimer linoleic diol to obtain “green” copolyester as a sustainable alternative to petroleum-based materials. Proton nuclear magnetic resonance (1H NMR) analysis confirmed that, using enzyme as a catalyst, we were able to produce multiblock copolymer and gel permeation chromatography (GPC) measurements revealed number-averaged molecular mass to be 25,000 g/mol. Additionally, differential scanning calorimetry (DSC) analysis revealed low-temperature glass transition (Tg) of soft segments and high melting point (Tm) of hard segments which indicate on two-phase morphology. Furthermore, cytotoxicity test using L929 murine fibroblasts was conducted on extracts of obtained PBS-DLS copolymer, indicating excellent biocompatibility in vitro.

The active control of friction in oil-based lubricants was realized in the present study with the use of MoS2 particle additives and the application of an electric field. By modifying the surface charging state of the MoS2 particles, the dependence of potential-controlled boundary lubrication behavior on the electrical properties of the particles was demonstrated. For a diethyl succinate lubricant containing negatively charged MoS2 particles, the coefficient of friction (COF) was reduced by 60–70% when a positive potential was applied to a lower friction pair of copper plates. After modification with poly(diallyldimethylammonium chloride), the particles were positively charged, and the COF was reduced with the application of a negative potential. The mechanisms underlying the potential control of the COF were investigated by observing the distributions of the particle additives and characterizing the tribofilms formed at different potentials. Most of the charged particles were locally concentrated near the opposite pole, and this was reversed when the electric field changed. For locally high concentrations of MoS2 particles, a MoS2/MoOx tribofilm with a thickness of 100–500 nm and a loose structure formed on the lower friction pair, which significantly decreased the shear force during the friction process.

Succinate is a metabolite in tricarboxylic acid cycle (TCA) which plays a central role in mitochondrial activity. Excess succinate is known to be transported out of cytosol where it activates succinate receptor (SUCNR1) to enhance inflammation in various contexts. However, the intracellular role of succinate beyond an intermediate metabolite and prior being released extracellularly, is not well characterized. Lipopolysaccharide (LPS) stimulates the elevation of intracellular succinate levels. To reveal the function of intracellular succinate associated with LPS stimulated inflammatory response in microglial cells, we assessed the levels of ROS, cytokines production and mitochondrial fission in primary microglia pretreated with cell-permeable diethyl succinate mimicking increased intracellular succinate. Our results suggest that elevated intracellular succinate exerts a protective role in primary microglia by preventing their conversion into the pro-inflammatory M1 phenotype induced by LPS. This protective effect is SUCNR1 independent and mediated by reducing mitochondrial fission and cellular ROS production.

In this study, we evaluated the effect of addition of non-volatile compounds (sodium sulfite, tartaric acid, tannin, and glucose) on the rheological properties, release of aroma compounds, and color of the red wine. While determining the rheological properties of the supplemented samples, non-Newtonian fluidic and shear-thinning behavior of samples was noticed. The viscosity of these samples was found in negative correlation with the dose of addition of various non-volatile substances. The aroma profile of red wine after additions showed the change in the release of the nine key aroma compounds. Among them ethyl hexanoate, phenylethyl alcohol, octanoic acid, diethyl succinate, and ethyl octanoate were profoundly increased. Further, the color of red wines was improved in the presence of tartaric acid and tannin. Overall, supplementation of various substances during storage period of three different wines could enormously affect the sensory characteristics in a dose dependent manner. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s10068-018-0492-0) contains supplementary material, which is available to authorized users.

The objective of this study is to find appropriate surface potentials under which the ZDDP tribofim formation can be promoted efficiently with low ZDDP concentrations. Firstly, the boundary lubrication performance of ZrO2 ball and AISI 52100 steel plate in propylene carbonate (PC)/diethyl succinate (DES) blended with different ZDDP concentrations was investigated. With increase of ZDDP concentrations, the coefficient of friction and wear volume decreased and the tribofilm covered wider regions within the wear scars. Secondly, the boundary lubrication performance of the same tribo-system under different surface potentials was studied with a relative low ZDDP concentration. The coefficient of friction and wear decreased and the tribofilm-covered area increased along with the elevation of surface potentials, which is similar to the above mentioned concentration test results. Thirdly, the difference of ZDDP tribofilm chemical structures under different surface potentials were characterized by TEM, EDS and XPS. Finally, the mechanism of electrochemical effect on ZDDP tribofilm formation was discussed. It was considered that the effects of applied potentials on the adsorption of ZDDP additive and on activation energy of electrochemical reactions on the steel surface are the reasons for the observed electro-tribochemical experiment results.

Leoligin, a tetrahydrofuran lignan isolated from the root of the edelweiss plant, was synthesised from veratraldehyde (2 mol), diethyl succinate and 2-methyl-(Z)-2-butenoic acid. Initially, veratraldehyde and diethyl succinate underwent a Stobbe condensation to yield a C6-C5 acid which, after esterification, was condensed with a second molecule of veratraldehyde to generate a 2,3,4-trisubsituted γ-butyrolactone intermediate. Two reduction steps yielded a triol, which was ring-closed with tosyl chloride to form a hydroxymethyl-tetrahydrofuran, esterification of which with 2-methyl-(Z)-2-butenoic acid generated leoligin.

The aim of this study is to determine the profile of the volatile chemical compounds of Sodabi which is a traditional liquor widely consumed by people in the West Africa. Sodabi is a distilled product of fermented oil palm wine and its production is artisanal, using rudimentary equipment and recycled materials under precarious sanitary conditions. The production of this liquor is also often associated with adulterating practices such as the use of substrates other than palm wine and additives susceptible of producing toxic compounds in the end product. Chemical analysis of some samples of Sodabi showed a pH of 4.25±0.72; an acidity of 660±29.39 mg/L; a density of 0.9625±0.01; an alcohol contents of 44.31±1.95%v/v and a soluble solid contents of 31.45±2.44 mg/L. Volatile components of Sodabi samples were analyzed by gas chromatography-mass spectrometry and the results revealed forty-eight (48) components. The most abundant molecules was ethanol (98.95%v/v) and higher alcohols including 3-methylbutan-1-ol and 2-methylbutan-1-ol. Esters (methyl salicylate, diethyl succinate), aldehydes (furfural), ketones (butyrolactone) and phenols (phenol, 4-vinyl-2-methoxyphenol) were also determined. The compounds found in Sodabi were for the most part similar to those of industrial spirits. Trace amounts of methanol and lead were detected but the quantities of which were well below those associated with acute toxicity and representing no threat to the consumption of Sodabi.

Kaolin clay obtained from Kachchh, Gujarat was used as alumina and silica source to synthesize zeolite Y by hydrothermal method. The synthesis route comprised of the following steps: sulfuric acid treatment at 110 ​°C (4 ​h) for impurity removal followed by calcination at 600 ​°C for 4 ​h, thermal activation of kaolin into metakaolin by NaOH fusion at 850 ​°C (8 ​h); aging of reaction mixtures at 50 ​°C (24 ​h); crystallization (24 ​h) followed by washing and drying. The synthesized zeolite Y was examined by multiple characterization techniques which revealed a pore volume of 0.22 ​cm3/g with pore size of 2.89 ​nm having essential surface area of 320 ​m2/g, indicating a porous material having majority of micropores and remaining mesopores. The zeolite exhibited good catalytic activity for succinic acid esterification using ethanol to produce monoethyl and diethyl succinate. The conversion of SA (72%) and yield (60%) of valuable diester indicated good conversion rate and selectivity at moderate reaction conditions. Detailed structural comparison with zeolite Y synthesized using standard chemical route is also carried out. This work demonstrated an effective way of preparing environmentally benign porous zeolite Y having high surface area and pore volume that can be useful for catalytic applications.

In this work, a pendant drop apparatus was developed and tested by the surface tension measurement of toluene. Then, the surface tensions of 2-Methoxyethanol, 2-Methoxyethyl ether, 2-Ethylhexyl acetate and Diethyl succinate were measured in the temperature range from (303.15–393.15) K. The surface tension correlations were developed as a function of temperature with the experimental data, and the average absolute deviations were 0.041 mN m−1, 0.064 mN m−1, 0.041 mN m−1 and 0.052 mN m−1 for 2-Methoxyethanol, 2-Methoxyethyl ether, 2-Ethylhexyl acetate and Diethyl succinate, respectively.

2-(Aryl(thiophen-2-yl)methyl)succinic acids (4a – 4d), 3-(aryl(thiophen-2-yl)methyl)dihydrofuran-2,5-diones (5a – 5d), 7-aryl-4-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-6-carboxylic acids (6a – 6d), and ethyl 7-aryl-4-oxo-4,5,6,7-tetrahydrobenzo[b]thiophene-6-carboxylates (7a – 7d) were synthesized via Stobbe condensation of aryl(thiophen-2-yl)methanones and diethyl succinate. The newly synthesized compounds (5a – 5d, 6a – 6d, and 7a - 7d) were screened in vitro for their antimicrobial and antioxidant properties. Compounds 5b, 6d, and 7d exhibited promising antifungal and antibacterial activity against various microorganisms tested. Compounds 7d and 7b showed remarkable DPPH radical scavenging abilities.

Further enhance the oxygen content (OC) of the conventional B5 palm oil biodiesel is the key to attain greener emissions in future. Diethyl succinate (DES) and 1-octanol (OCT) is designed to blend with B5 to address this issue. In this study, the optimum binary and ternary blends (with higher OC) of B5 with DES and/or OCT are obtained using a computer-aided decomposition-based optimization. The predicted fuel properties (density, kinematic viscosity, higher heating value (HHV) and flash point) and engine performances including fuel efficiency: brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) and emissions of nitrogen oxides (NOx), carbon monoxide (CO) and un-burnt hydrocarbon (UHC) of the optimum blends are evaluated experimentally. 2-ethylhexyl nitrate (2EHN) is used to enhance the cetane number of the optimum blends to improve their combustion quality. Ternary blend of B5 with DES and OCT could attain higher OC than binary blends with satisfied target fuel properties. The predicted fuel properties such as density, HHV and flash point are well agreed with experimental value except kinematic viscosity. The designed optimum blends generally have greener emissions than B5 while having similar fuel efficiency with B5. T1A ternary blend (B5 = 70.0%; OCT = 24.1%; DES = 5.9% with 0.20% 2EHN) appear as the most promising green diesel blend owning to its greener emissions (NOx, CO and UHC) and similar fuel efficiency with B5.

This work provides experimental data and thermodynamic modeling on phase equilibria of binary mixtures that are relevant for esterification reactions. The components under investigation include water, succinic acid (SA), ethanol (EtOH), 1-butanol (1-BuOH), and the diesters of SA, namely, diethyl succinate (DES) and dibutyl succinate (DBS), respectively, as well as the organic solvents acetonitrile (ACN) and tetrahydrofuran (THF). Liquid–liquid equilibria (LLE) of water/DBS were measured at ambient pressure for temperatures between 313 and 353 K. Isobaric vapor–liquid equilibria (VLE) were measured for the binary systems ACN/DES, ACN/DBS, 1-BuOH/DBS, and THF/DBS at pressures of 10 or 20 or 30 kPa. Temperature ranges for the isobaric VLE varied between 300 and 500 K. The measured data and phase equilibria reported in literature were accurately modeled using perturbed-chain statistical associating fluid theory (PC-SAFT). For this purpose, pure-component PC-SAFT parameters, which were not already reported in ...

The presences of CO2 and H2S are major contamination in synthesis gas, natural gas or other industrial gases, which can lead to economic, environmental losses, corrosion of the equipments and other problems. Therefore, it will be important to remove these acid gases from the industrial gases stream. In this work, the constant-volume method was used to determine the solubility of CO2 and H2S in propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and diethyl succinate (DES) at 298.15–328.15 K and the pressures up to about 1 MPa. The quantum chemical calculations at DFT/B3LYP level of theory using 6 − 311 + G(d,p) basis sets are taken to investigate the interaction mechanism between CO2/H2S and the carbonates from a molecular point of view. The results show that the CO2 or H2S absorption in these solvents is physical process and the solubility is in the same order: PC

The finite natures of fossil fuels and their contributions to anthropogenic climate change are driving the development of biofuels. However, because of the inherent issues with current biofuels, such as ethanol and biodiesel, innovative replacements are being increasingly sought. Recently, four esters produced from fermentation, namley diethyl succinate, dibutyl succinate, dibutyl fumarate and dibutyl malonate, were reported to have suitable physical properties as a substitute for conventional diesel fuel. Although the physical properties are indicative of the fuel behaviour, the determination of the combustion emissions and the performance of a fuel using controlled engine testing is vital. In this investigation, the engine performance and emissions produced from the most viable fuel, namely diethyl succinate, were examined. Diethyl succinate was blended with diesel in a 20 vol % blend, owing to the low cetane number of diethyl succinate, and the emissions established in pseudo-steady-state conditions using a 2.0 L turbocharged direct-injection EURO 3-compliant light commercial vehicle equipped with a direct-injection common-rail diesel engine. When using the diesel–20 vol % diethyl succinate blend, the fuel demand and the wheel force were higher for the majority of engine speeds than those of diesel, whereas the exhaust gas temperatures were lower. The difference between the exhaust gas temperature for the diesel–20 vol % diethyl succinate blend and that for diesel increased with increasing pedal demand. In comparison with the carbon monoxide emissions from petroleum-derived diesel, the carbon monoxide emissions obtained when using the diesel–20 vol % diethyl succinate blend were reduced, most probably because of more complete combustion due to the increased oxygen content. However, the total hydrocarbon emissions and the mono-nitrogen oxide emissions were shown to increase on using the diethyl succinate blend. Both of these factors were presumably due to the lower cetane number of the fuel, although the increase in the total hydrocarbon emissions was deemed negligible because of the low amount produced by both fuels.

In this work, we present a mild one-step enzymatic-catalyzed copolymerization of diethyl succinate, 1,4-butanediol and p-dioxanone (PDO) to synthesize poly(p-dioxanone-co-butylene-co-succinate) copolyesters. Their chemical structure, triad distributions, and molecular weight of the copolyesters are characterized by 1H NMR, 13C NMR and GPC. All copolyesters have narrow molecular weight polydispersity (1.3–1.5) and higher molecular weight (Mw) values (23700–33200 g mol−1), which are well controlled by varying the amount of PDO units from 9 to 30 mol%. NMR, DSC, and XRD results show that copolyesters are semicrystalline random copolyesters and thermal properties depended on their composition. Furthermore, the degradation rate of the poly(p-dioxanone-co-butylene-co-succinate) are enhanced compared to PBS.

Candida antarctica lipase B was successfully employed for the first time as a biocatalyst to obtain high molecular weight poly(butylene succinate-co-dilinoleic succinate) (PBS : DLS) copolyester via a two-stage method in a diphenyl ether solution from diethyl succinate, 1,4-butanediol, and dimer linoleic diol. The final hard to soft segments were close to the initial feed ratio as confirmed by 1H NMR and FTIR measurements. Thermal analysis revealed the presence of two transitions typical for thermoplastic elastomers: a low temperature glass transition and high temperature melting point. In addition, the optimized synthetic protocol ensured high reaction yield (>74%) and molecular weight (Mw > 34 × 103 g mol−1) high enough to process the copolymer into electrospun mats without defects. The enzymatically synthesized PBS : DLS was able to be processed at 20–25 w/v% concentrations into fibres and depending on the type of solvent, the fibre diameter was controlled in the range of 0.3 to 0.6 μm.

Background Scion physiology and grape quality are impacted by rootstock choice. There is little available information about the effects of rootstock on wine volatile composition, particularly when comparing grafted with own-rooted grapevines. This field trial was aimed at studying the influence of rootstock choice on volatile composition of Merlot wines. Results Wines made from grapes harvested from own-rooted grapevines had the lowest content of (E)-3-hexenol, diethyl succinate and total ethyl esters and the highest content of 1-pentanol, 1-hexanol, (Z)-3-hexenol, diethyl malate and acetovanillone. Rootstocks such as 99R and 140Ru led to a higher content of total ethyl esters in wines followed by 110R, 1103P and Gravesac. According to odor activity values, Merlot wines were characterized by roses, sweat, cheese and banana aromas. Conclusions This work provides valuable information about the potential impact of rootstocks on wine volatile composition for Merlot wines. © 2020 Society of Chemical Industry.

“Beverages obtained from the partial dealcoholization of wine” are those drinks whose final alcoholic degree after dealcoholization is lower than that of a wine and higher than or equal to 0.5% v/v. When the total alcoholic degree is lower than 0.5% v/v the denomination is “Beverages obtained from the dealcoholization of wine”. The practices to be authorized for the production of these drinks with the dealcoholized wine fractions are currently being studied at OIV. The characterization of the composition of these fractions is essential to identify the necessary corrective practices. The present work was aimed at monitoring the losses of the main volatile compounds of a Chardonnay wine with the proceeding of the dealcoholization process by vacuum distillation. The wine was subjected to total dealcoholization, and during the process the evaporated fractions, re-condensed at 9 ∘C, were collected in aliquots of 1.25 L each. The ethanol content of each fraction was measured, and for the first 20 fractions the content in volatile compounds was determined with GC-MS. The results show that the losses of volatile compounds during the dealcoholization process follow different trends depending on the molecules considered. The most volatile compounds, generally with the lowest perception thresholds, were mainly present in the first evaporated fractions. The greatest losses concerned isoamylacetate, ethyl hexanoate and ethyl octanoate. Conversely, a greater number of molecules were present at similar concentrations in the different fractions, and their losses followed a linear or sometimes exponential trend: in particular, these compounds included n-hexanol, 2-phenylethanol, diethyl succinate and medium chain fatty acids (hexanoic, octanoic and decanoic acids). In the wine dealcoholized at 3.36% v/v (loss of ethanol equal to 7.43% v/v, corresponding to the 20th and last recondensed fraction), some volatile compounds were no longer detectable or quantifiable; in particular, these compounds were isoamylacetate, ethylhexanoate, hexylacetate, n-hexanol and other alcohols with 6 carbon atoms and ethyl octanoate. Other compounds, such as hexanoic, octanoic and decanoic acids, and, in particolar, β-phenylethanol, benzylic aalcohol and γ-butyrolactone, underwent lower percentage losses than those of ethanol. The dealcoholization process can therefore deeply modify the original aromatic profile of the wines, intervening on the absolute concentration and on the relative ratios of the single molecules.

Biobased aliphatic sulfonated oligoesters with 10 to 30% of sulfonated units were synthesized by melt polycondensation of biobased monomers such as diethyl succinate, z-octadec-9-enedioic acid, dimer fatty acid, sodium (sulfonated dimethyl succinate), and various diols like 1,4-butane diol and isosorbide. Structural characterization of the resulting oligoesters was determined by 1H NMR spectroscopy and MALDI-TOF MS technique. Showing a regular structure, the nature of the different expected species present in the macromolecular structure allowed the detection of etherification and cyclisation side reactions. The study of the thermal properties indicates that the resulting oligoesters are amorphous or semicrystalline that essentially depend on the nature of monomers. Films of oligoesters treated in acidic, basic, and natural media at 37°C indicate that the remaining weight depends essentially on the composition of oligoesters. Finally, sulfonated oligoester was used to prepare a biobased poly(ester-urethane) thermoset, a material having tunable properties.

This research reports the effect of the cation exchange treatment in Tempranillo wines during the aging period in oak barrels. The control wine and the mixtures with different percentages (5, 10 and 20%) of wine treated by a cation exchange resin (permeate wine) were evaluated. In general, a greater acidity, color and tartaric stability, and a lower mineral content were observed in the treated wines, especially in those with 20% of permeate wine. In addition, during the entire aging time, the decrease in potassium and magnesium cations stood out. A higher concentration of aromatic compounds such as hexyl acetate, isobutanol, 2-phenylethyl alcohol, ethyl isovalerate and diethyl succinate was observed in treated wines after six months of aging. The two last compounds reached the highest concentrations when the percentage of permeated increased and reached values up to 23 μg/L for ethyl isovalerate and up to 3186 μg/L for diethyl succinate. In addition, the perception thresholds of these esters were exceeded in all wines. The use of cation exchange resins seems to be an effective industrial alternative to produce balanced red aged wines in a climate change scenario.

An alternative process for the production of poly(butylene succinate) (PBS) was herein applied, divided in two stages, both sustainable and in accordance with the principles of green polymerization. The first stage involved the enzymatic polycondensation of 1,4-butanediol and diethyl succinate, using immobilized Candida antarctica lipase B as a biocatalyst. The suitability of two different solvents (isooctane, toluene), as well as the bulk (solvent-free) system were examined at different reaction temperatures (40 °C, 50 °C, 60 °C), leading to the selection of isooctane as solvent and 50 °C as reaction temperature for the enzymatic prepolymerization step. The formed prepolymers were then submitted to bulk post-polymerization in order to upgrade their quality in terms of molecular weight and thermal properties. The final product was a PBS grade with weight-average molecular weight at ca. 5000 g/mol, melting point at 104 °C and mass fraction crystallinity at 70%, free of thermal degradation and metal catalyst residues.

Ternary liquid-liquid equilibrium (LLE) systems composed of (water + formic acid + ester or alcohol), exhibiting experimental phase diagrams of type 1, have been studied at T = (298.2 ± 0.1) K and P = (101.3 ± 0.7) kPa. The equilibrium distribution of formic acid onto (water + solvent) two-phase system is better for dibasic ester (diethyl sebacate, diethyl succinate) as compared to monobasic ester (ethyl caprylate, ethyl valerate) and isoamyl alcohol. The thermodynamic models SERLAS, UNIFAC-original, NRTL, NRTL-modified and three-suffix Margules have been deeply tested for consistency in simulating the ternary LLE behavior. An immediate goal is to estimate the interaction parameters of molecular models from ternary data only using a genetic algorithm. The genetic algorithm identifies globally optimal values by producing a population of candidate solutions from given upper and lower bounds of the interaction parameters. The reliability of existing models has been analyzed statistically with respect to three physical extraction factors. Essentially, SERLAS, UNIFAC-original, NRTL, NRTL-modified and three-suffix Margules yield mean errors of 3.4%, 19.4%, 4.2%, 4.4% and 8.6%, respectively, enabling the ternary phase behavior to be simulated satisfactorily. The UNIFAC-original prediction is moderately precise. NRTL is especially effective in correlating both the two-phase envelope size and the tie line slope. While SERLAS has proven reasonably successful in reproducing the physical extraction factors, yielding about equally accurately estimates for each ternary system.

The enzyme-catalyzed synthesis of fully biobased poly(3-hydroxybutyrate-co-butylene succinate) (poly(HB-co-BS)) copolyesters is reported for the first time. Different Candida antarctica lipase B (CALB)-catalyzed copolyesters were produced in solution, via a one-step or a two-step process from 1,4-butanediol, diethyl succinate, and synthesized telechelic hydroxylated poly(3-hydroxybutyrate) oligomers (PHB-diol). The influence of the ester/hydroxyl functionality ratio, catalyst amount, PHB-diol oligomer chain length, hydroxybutyrate (HB) and butylene succinate (BS) contents, and the nature of the solvent were investigated. The two-step process allowed the synthesis of copolyesters of high molar masses (Mn up to 18 000 g/mol), compared to the one-step process (Mn ∼ 8000 g/mol), without thermal degradation. The highest molar masses were obtained with diphenyl ether as solvent, compared with dibenzyl ether or anisole. During the two-step process, the transesterification rate between the HB and BS segments (i) ...