Isomeric Butanediols Research Articles

Volumetric, Optical and Spectroscopic Properties of Binary Mixtures of Glycerol with Butanediol Isomers

Volumetric, Optical and Spectroscopic Properties of Binary Mixtures of Glycerol with Butanediol Isomers

The effect of choline chloride-butanediol based deep eutectic solvents on ultrasound-assisted extraction, antioxidant activity and stability of anthocyanins extracted from Perilla frutescens (L.) Britt.

To explore the relation between anthocyanins extraction performance and physicochemical properties of choline chloride (ChCl)-butanediol deep eutectic solvents (DESs), sixty formulas consisting of ChCl with four butanediol isomers (1,3-butanediol, 1,4-butanediol, 2,3-butanediol, or 1,2-butanediol) at different molar ratios (ChCl/butanediol) and different amounts of water were examined. In this study, 1,3-butanediol was selected as the most promising hydrogen bond donor for the preparation of DESs. The highest anthocyanins content (9.97 ± 0.04 mg/g) was obtained using the DES composed of ChCl and 1,3-butanediol with 1:2 M ratio containing 50% water (DES-2 (50%)) coupled with ultrasound assisted extraction (UAE). The anthocyanins extracted by DES-2 (50%) presented highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) antioxidation activity (1.88 ± 0.01 μM TE/g DW), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) antioxidation activity (5.10 ± 0.09 μM TE/g DW), ferric reducing/antioxidant power (FRAP) antioxidation activity (28.39 ± 0.21 μM TE/g DW). Comparative investigations on stability of anthocyanins proved that DES-2 (50%) offers outstanding advantages over acidified ethanol. After storage at 4°C for 6 days, the remaining fraction of the anthocyanins extracted by DES-2 (50%) (92.01 ± 0.52%) was higher than anthocyanins extracted by ethanol (84.25 ± 0.57%).

Effect of position of OH group in isomeric butanediols on intermolecular interaction with Choline Acetate: A thermodynamic study at different temperatures

The prominent effect of the position of hydroxyl groups in isomeric butanediols i.e.1,3-butanediol (1,3-BTD), 1,2-butanediol (1,2-BTD) and 2,3-butanediol (2,3-BTD) on intermolecular interactions with Choline Acetate has been investigated using various thermophysical parameters such as density ρ, speed of sound u, refractive index nD and specific conductivity κ over different concentration range and at temperatures varying from 293.15 to 323.15 K at atmospheric pressure. To gain further insight the derived parameters such as apparent molar volumes Vϕ, apparent molar isentropic compressibilities Ksϕ, and their infinite parameters mainly limiting apparent molar volumes at infinite dilution Vϕo, limiting apparent molar expansibilities Eϕo, limiting isentropic compression Kϕo, molar refraction Rm and infinite molar conductance ̂mo values have been calculated. The least values obtained for apparent molar volumes and compressibilities in case of 1,3-BTD mixtures are attributed to its highest ability to form intramolecular hydrogen bonding among isomeric butanediols and thus lesser availability to interact with Choline Acetate molecules. However for 2,3-BTD and 1,2-BTD binary mixtures the results have been explained on the basis of hydrophobic or iceberg effect where alkyl groups are present either on one end (1,2-BTD) or at both ends (2,3-BTD) while OH groups are located at vicinal carbon atoms.

Structure and functionality of oat protein extracted by choline chloride‒dihydric alcohol deep eutectic solvent and its water binary mixtures

This research reports an eco-friendly oat protein extraction method using choline chloride (ChCl)–butanediol deep eutectic solvents (DESs) and DES/water binary mixtures. Eighteen formulas consisting of ChCl with butanediol isomer (1,2-butanediol, 1,4-butanediol, or 2, 3-butanediol) in the absence or presence of water at different molar ratio were examined for the synthesis of DESs and binary mixtures. We found that 6 formulae can be fabricated at a ChCl–butanediol molar ratio of 1:3 independent of water presence, and that they had better oat extraction performance with 90 min extraction at 80 °C. Under the optimal conditions, we further assessed the impact of butanediol isomers and water addition on the structure characteristics and functionalities of extracted oat protein. The results suggested that oat protein extracted by ChCl−1,4-butanediol/water binary mixture had highest protein content, solubility, foaming capacity and stability. Our pilot findings provide crucial support to our hypothesis that the isomer of hydrogen bond donor is critically involved in the properties of oat protein the DES and the binary mixtures extracted, which pave the way for the future application of DES in protein extraction.

Thermodynamic study of oxygenised fuel additives (isomeric butanediols with ethyl acetate) at 298.15-323.15K

ABSTRACT Densities, ρ, and Speeds of Sound, u, were measured for pure liquids of ethyl acetate, (EtOAc), 1,2-butanediol, (1,2-BD), 1,3-butanediol, (1,3-BD), 1,4-butanediol, (1,4-BD) and their binary mixtures {x 1 EtOAc + x 21,2-BD}, { x 1 EtOAc + x 21,3-BD}, and { x 1 EtOAc + x 21,4-BD} over the composition (EtOAc) and at temperatures (298.15–323.15) K at pressure 0.1 MPa. To understand the molecular interactions of solute–solvent, measured excess properties such as the excess molar volume, , excess isentropic compressibility, , excess speeds of sound, , excess molar isentropic compressibility, , thermal expansion coefficient, , excess thermal expansion coefficient, were calculated and fitted using the Redlich–Kister equation. For better understanding, also calculated partial molar volumes/isentropic compressibilities, and their excess properties at infinite dilution were measured. These parameters have been used to understand the interactions in the mixtures qualitatively. The experimental findings were compared through the usage of theoretical model developed by Prigogine–Flory–Patterson (PFP).

Effect of temperature and position of OH group in isomeric butanediols in intermolecular interactions with 2-chloroaniline: A thermodynamic, DFT and molecular dynamics approach

The pronounced effect of the position of the hydroxyl groups in isomeric butanediols (1, 2-butanediol (12BDL), 1, 3-butanediol (13BDL) and 1, 4-butanediol (14BDL)) in the formation of hydrogen bonds with 2-chloroaniline (2CA) was investigated by using experimental and computational methods. The density (ρ) and speed of sound (u) in binary mixture was determined at T = (303.15–318.15) K and at atmospheric pressure p = 0.1 MPa. Values of excess molar volume (VmE), and excess isentropic compressibility (ksE) were determined by using experimental data. It was observed that these excess properties (VmEksE) departs negatively from the ideal mixture which indicates the formation of intermolecular hydrogen bonds. The volumetric properties like excess partial molar volume (V‾m,1EV‾m,2E), partial molar volume (V‾m,10,V‾m,20) and excess partial molar volume (V‾m,10EV‾m,20E) are derived at infinite dilutions. Quantum mechanical approach was used to study the intermolecular hydrogen bond interactions in self and cross-associated complexes of 2-chloroaniline and isomeric butanediols with the aid of DFT in the gas phase, while classical molecular dynamic simulations were carried out in the liquid phase. Experimental, quantum mechanical and classical molecular dynamic methods are used to investigate the formation of a hydrogen-bonded network between 2-chloroaniline and isomeric butanediols mixtures. The investigated results were further confirmed by the existence of hydrogen bonding evolution between 2-chloroaniline and isomeric butanediols through FT-IR Spectral studies. The Fourier transform Infrared spectroscopic data strongly confirms and support the existence of intermolecular hydrogen bonding and molecular associations between component molecules.

Note on “Acoustic and volumetric study of renewable oxygenated fuel additives at (298.15–323.15) K: Isomeric butanediols with ethylbutyrate” [J. Chem. Thermodyn. 136 (2019) 100–115

Errors in the volumetric properties and excess molar isentropic compressibility properties reported in Tables 5 and 6 of the published paper are identified. New calculated values are provided for Tables 5 and 6.

Acoustic and volumetric study of renewable oxygenated fuel additives at (298.15–323.15) K: Isomeric butanediols with ethylbutyrate

Today biofuels are emerging in an exponentially manner in order to replace the fossil fuels. Biofuels are composed of several organic compounds containing wide variety of functional groups. The interactions existing among these compounds play a significant role in the efficiency of the biofuels. In this paper, the authors presented the new findings related to interactions existing in ethylbutyrate and α, ω-alkanediols in pure state as well as in their mixtures. Densities and speeds of sound at various temperatures (298.15–323.15) K and at ambient pressure 0.1 MPa have been measured for these mixtures. From experimental data, the excess properties such as excess molar volume, VmE, excess isentropic compressibility, κsE, excess molar isentropic compressibility, Ks,mE, excess speed of sound, uE, and excess isobaric thermal expansion, αpE, of the investigated mixtures were calculated. All the excess parameter values were fitted using the Redlich-Kister polynomial smoothing equation. The results were analysed in terms of molecular interactions. The partial molar volumes, V¯m,1 and V¯m,2, partial molar isentropic compressibilities, K¯s,m,1 and K¯s,m,2, excess partial molar volumes, V¯m,1E and V¯m,2E and excess partial molar isentropic compressibilities, K¯s,m,1E and K¯s,m,2E over whole composition range; the excess partial molar quantities of the components at infinite dilution have been calculated. The variations of these parameters with change in composition and temperature have been discussed in terms of intermolecular interactions prevailing in these mixtures. The VmE values for these mixtures were also calculated by using Prigogine–Flory–Patterson (PFP) theory and the results were compared with experimental findings.

Biobutanediol-mediated liquefaction of empty fruit bunch saccharification residues to prepare lignin biopolyols

Saccharification residue from empty fruit bunch (EFB) was liquefied with bio-butanediol to produce lignin biopolyols for the preparation of biopolyurethane. To substitute petroleum-derived polyhydric alcohols, butanediol isomers (1,4-butanediol, levo-2,3-bio-butanediol, and meso-2,3-bio-butanediol) or PEG#400-blended butanediol isomers were used as liquefaction solvents in the presence of sulfuric acid catalyst. Lignin biopolyols with a conversion of 63.3%, a hydroxyl number of 582.7mgKOH/g and an acid number of 21.7mgKOH/g were obtained under the optimal condition consisting of 25% biomass loading, 3% acid loading, and a temperature of 150°C for 120min when liquefied with 1,4-butanediol/PEG#400 blended solvent (9/1, w/w). When the levo-2,3-bio-butanediol solvent was used in the absence of PEG#400, the highest conversion, 68.9%, was obtained. Lignin biopolyol-based biopolyurethanes were synthesized with toluene diisocyanate. FT-IR analysis revealed that EFB lignin biopolyols liquefied with bio-butanediols were suitable monomers for the preparation of biopolyurethane.

Partial Molar Isentropic Compressions and Partial Molar Volumes of Isomeric Butanediols at Infinite Dilution in Water at Temperatures T = (278 to 318) K and Atmospheric Pressure

Speed of sound and density data for dilute aqueous solutions of all four isomeric butanediols derived from n-butane (butane-1,2-diol, butane-1,3-diol, butane-1,4-diol, butane-2,3-diol) were obtained using an Anton Paar DSA 5000 vibrating-tube densimeter and sound analyzer in the temperature range from (278.15 to 318.15) K and at atmospheric pressure. Standard molar isentropic compressions and standard molar volumes were evaluated from the measured data. Relations between the two standard quantities and molecular structures of the solutes are discussed.

Miscibility of tetrafluoroborate ionic liquids with dihydroxy alcohols

In this paper, we have carried out a study on miscibility of ([bmim]+, [hmim]+, [omim]+)[BF4]− ionic liquids and dihydroxy alcohols: vicinal (1,2-diol) — C2(1,2)(OH)2 to C6(1,2)(OH)2, terminal (1,ω-diol) — C2(1,2)(OH)2 to C5(1,5)(OH)2 and butanediol isomers. Phase diagrams were determined at atmospheric pressure over the temperature range (270 to 340) K using the cloud-point method. LLE data for all 18 binary systems determined show the same behavior, representing phase diagrams with the upper critical solution temperature (UCST). With increasing chain length in C-3 position of the imidazolium cation, the UCST shifts toward higher temperatures for the systems with ethane-1,2-diol. Contrary, for the systems of longer diols with hydroxyl group in 1,2-position (propane-1,2-diol, butane-1,2-diol, pentane-1,2-diol and hexane-1,2-diol) improvement of miscibility was observed. The influence of different characteristics of alcohols and ILs, including cation alkyl chain length, alcohol chain length, and relative position of both OH groups in diol was also studied.

Glass-forming ability of butanediol isomers

In this study, the thermal behavior of butanediol isomers is investigated for temperatures ranging from 103 to 303 K using differential scanning calorimetry, complemented, when necessary, by polarized light thermal microscopy. The butanediol isomers display quite different thermal behaviors: for 1,2- and 1,3-isomers, glass transition is the only thermal event observed; for 1,4-butanediol, crystallization occurs on cooling even at a high scanning rate and no glass formation was detected; and for the 2,3-isomer, glass or crystal formation is dependent on the experimental conditions employed. The glass-forming ability of the isomers is correlated with data available on their molecular symmetry.

Speed of Ultrasound and Internal Pressure of Propanediol and Butanediol Isomers under Elevated Pressures

The phase speed of an ultrasound wave depends on the elastic properties of the material. It is a significant source of information on the molecular structure of the liquid and on physical and chemical processes occurring in the liquid phase. Speed of ultrasound measurements carried out as functions of temperature and pressure enable also the determination of pρT relationships. Moreover, the measurements of the speed of ultrasound permit the investigation of very subtle effects such as, for example, stacking effect [1] or the effect of the position of OH groups in diol isomers on the physicochemical and thermodynamic properties of the pure compounds or their mixtures [2]. However, it requires measurements of adequate high accuracy and precision [3–6]. One of the convenient methods for the determination of the internal pressure is the acoustic one, i.e. the use of speed of ultrasound in conjunction with the density, isobaric heat capacity, and isobaric expansibility. The starting point is the combination of the low-frequency speed of ultrasound and density, which yields the isentropic compressibility (the Newton–Laplace equation). Then the latter may be combined with the isobaric expansibility and the isobaric heat capacity to yield the isothermal compressibility and finally the internal pressure (more details can be found elsewhere [7–11]). The so-called direct methods of determination of internal pressure are very inconvenient. Therefore, these methods are rather rarely used.

Molecular Structure of Butanediol Isomers in Gas and Liquid States: Combination of DFT Calculations and Infrared Spectroscopy Studies

Density functional theory (Becke3LYP/6-311++G**) conformational analysis was carried out for all positional butanediol isomers. Taking into account the relative populations of the most stable conformers at 298.15 K, the weighted mean enthalpies of each butanediol isomer in the gas state were computed. Combining these results with the experimental values for the enthalpies of vaporization at 298.15 K, an estimate of the enthalpy of each of the butanediol isomers in the liquid state was obtained and discussed. The insight into the structural changes at the molecular level from the isolated molecule to the condensed state was improved by an infrared spectroscopy study in the OH stretching region, which was carried out for a wide range of concentrations of carbon tetrachloride solutions and pure liquids. The spectroscopic studies essentially confirmed the results derived from the combination of the computational and calorimetric studies.

Thermodynamic and aggregation properties of sodium dodecyl sulfate in aqueous binary mixtures of isomeric butanediols

The effect of aqueous binary mixtures of isomeric butanediols on the micellization of sodium dodecyl sulfate has been investigated. Conductivity and fluorescence techniques were employed to determine the critical micellar concentration, the degree of dissociation of the counterions and the aggregation numbers of the surfactants in these binary blends. Differential conductivity plots were employed to distinguish between the cooperative and the stepwise aggregation process of the surfactant in each solvent system. The mass-action model was employed to calculate the hydrophobic and the electrostatic contributions to the Gibbs energy of micellization as well as the monomer and the counterion concentrations in the postmicellar region. The thermodynamic parameters calculated for each system indicate that the micellization process occurs more readily in the presence of cosolvent owing to the formation of mixed micelles.

Ultrasonic velocity and absorption in the binary mixtures of 1-butanol with isomeric butanediols at 298.15 K

From the early days of ultrasonic technology, ultrasonic velocity and ultrasonic absorption have been a rich source of information on the structure and condition of the materials trough in which the ultrasonic waves are propagated. Here an investigation into binary mixtures (in the whole concentration range) of 1-butanol with 1,2-butanediol and 2,3-butanediol at 298.15 K is reported. For the ultrasonic velocity measurements at 2.15 MHz, the pulse-echo-overlap method was used and the ultrasonic absorption in the frequency range 10–200 MHz was determined by the standard pulse technique, where the amplitude of the first transmitted pulse was registered as a function of distance. The results were compared with the previous data for 1-butanol with 1,3-butanediol and 1,4-butanediol and discussed in terms of molecular interactions in highly associated liquids.

Calorimetric and NMR Investigations of the Micellar Properties of Sodium Dodecyl Sulfate in Aqueous Mixtures of Isomeric Butanediols

The enthalpies (ΔmicH°), entropies (ΔmicS°), and Gibbs energies (ΔmicG°) of micelle formation have been determined for a series of sodium dodecyl sulfate (SDS)/butanediol isomer micelles using isoperibol solution calorimetry. Nuclear magnetic resonance (NMR) paramagnetic relaxation enhancement experiments were used to determine the degree of solubilization of the isomeric butanediols (BTDs) in a 0.100 M solution of SDS micelles. In addition, the manner in which the butanediol cosolvents interact with SDS micelles, as a function of the position of substitution of the hydroxyl groups on the four-carbon backbone, has been examined closely via 13C NMR spectroscopy. All of these results are interpreted in terms of the differences in the interaction of the isomeric butanediols with SDS micelles because of the addition of the second hydroxyl headgroup on the four-carbon backbone of the alcohol, when compared to the well-studied SDS/1-butanol (C4OH) mixed micellar system.

Ultrasonic velocity and volumetric properties of isomeric butanediols plus water systems

Ultrasonic velocities and densities of binary aqueous solutions of isomeric butanediols were measured in the temperature range 298-318 K at 10 degree intervals over the entire composition range, and 5 degree intervals in the water-rich region. The experimental data in the dilute region, with mole fraction of water less than 0.1, was analysed to determine the partial molar volumes and adiabatic compressibilities of water at infinite dilution. The standard thermodynamic transfer functions were calculated to evaluate the environment of water at infinite dilution in these systems. From the compressibility isotherms, as a function of temperature in the water-rich region, the formation and the composition of clathrate-like structures in the liquid solutions was determined, and the nature of these structures was discussed.Key words: ultrasonic velocity, adiabatic compressibility, density, partial molar quantities, standard thermodynamic transfer functions.

Thermodynamic properties of binary mixtures of butanediols with water

Ultrasonic velocities and densities at five different temperatures over the entire composition range for aqueous solutions of 1,2, 1,3, 1,4, and 2,3 butanediols were measured. Excess volumes and adiabatic compressibilities were calculated using the experimental data. Apparent and partial molar volumes and compressibilities were analyzed to evaluate the departure from ideal solution behavior. From the analysis of the results, the interactions of isomeric butanediols with water are discussed in terms of the placements of hydroxyl groups in the isomeric butanediol molecules.

Viscosity, Surface Tension, and Refractive Index Measurements of Mixtures of Isomeric Butanediols with Water

Solution properties of aqueous mixtures of isomeric butanediols have been investigated employing viscosity, surface tension, and index of refraction measurements as functions of temperature. The deviation of viscosity, surface tension, and molar refraction from ideal solution behavior is evaluated from the experimental data. The deviation from ideality is discussed in terms of molecular interactions between the components. Surface activity of the diols is evident from the surface tension measurements. It is found that the degree of hydrophobicity of the diols varies in the order 1,2 > 2,3 > 1,3 > 1,4. The strength of interaction of diols with the water varies in the order 2,3 > 1,4 ≃ 1,3 > 1,2.