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Excess molar enthalpies, , of binary liquid mixtures containing as component 1 ethylene glycol, propylene glycol, di(ethylene glycol), tri(ethylene glycol), tetra(ethylene glycol), or some PEGs, such as PEG200, PEG300, PEG400, PEG600, and 2-phenylethyl alcohol (2), have been measured over the entire range of mole fraction x1 at 308.15 K and at atmospheric pressure, using a flow microcalorimeter. The values of vary from a value of −600 J·mol-1 (mixture containing PEG600) up to a maximum of 254 J·mol-1 (mixture containing propylene glycol) decreasing as the chain length of glycols or PEGs increase. Curves are not symmetric, and in the case of mixtures containing PEGs, an intersection among the curves at x1 ≈ 0.65 has been observed. Results were fitted to the Redlich−Kister polynomial to estimate the adjustable parameters and the standard deviations between experimental and calculated values. Qualitative discussion of H bonding in the liquid state is given.

Excess molar enthalpies, H-m(E), were determined as a function of molar fraction at 308.15 K and at atmospheric pressure for the binary mixtures containing dimethyl sulfoxide with ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, poly(ethylene glycol)-200, poly(ethylene glycol)-300, poly(ethylene glycol)-400, and poly(ethylene glycol)-600. All curves are negative over the entire composition range with minima ranging from -430 J.mol(-1) (propylene glycol) up to -1080 J.mol(-1) (poly(ethylene glycol)-600). The results were correlated using the Redlich-Kister polynomial, and the adjustable parameters were obtained by the least-squares method. The dependence of H-m(E) on mixture composition is qualitatively discussed in terms of molecular interactions.

Densities, ρ, viscosities, η, refractive indices, nD, and excess molar enthalpies, , of binary mixtures containing methyl tert-butyl ether (MTBE) + α-pinene (2,6,6-trimethylbicyclo[3.1.1]hept-2-ene), + β-pinene (6,6-dimethyl-2-methylenebicyclo[3.1.1]heptane), + p-cymene [1-methyl-4-(1-methylethyl)benzene], + (S)-(−)-limonene [(−)-1-methyl-4-(1-methylethenyl)cyclohexene], + 1,8-cineole (1,3,3-trimethyl-2-oxabicyclo[2.2.2]octane), and + linalool (3,7-dimethyl-1,6-octadien-3-ol) were determined at 298.15 K and at atmospheric pressure using a digital density meter, a Schott measuring system, an Abbe refractometer, and a flow microcalorimeter, respectively. The excess molar volumes, , the deviations in viscosities, Δη, and in refractive indices, ΔR, and the excess molar enthalpies, , were calculated from experimental measurements. Results were fitted to the Redlich−Kister equation to obtain the adjustable parameters and standard deviations. Results were also qualitatively discussed in terms of molecular intera...

Excess molar enthalpies, , and excess molar volumes, , of binary mixtures containing 1,3-dioxolane or 1,4-dioxane + α-pinene, + β-pinene, or + p-cymene were determined at (298.15 and 313.15) K and at atmospheric pressure over the entire composition range using a flow microcalorimeter and a digital density meter. and are always positive, and the temperature dependence is more marked for values. Results were fitted to the Redlich−Kister polynomials to obtain the binary adjustable parameters and the standard deviations

Excess molar enthalpies, , and excess molar volumes, , of binary mixtures containing dimethyl carbonate (DMC), or diethyl carbonate (DEC) + α-pinene, + β-pinene, or + p-cymene have been determined using a flow microcalorimeter and a digital density meter at atmospheric pressure and at (298.15 and 313.15) K. All and data are positive and show symmetrical curves versus composition. The influence of temperature is marked for volumetric measurements while almost negligible for enthalpic data. Results have been correlated using the Redlich−Kister polynomial to estimate the binary interaction parameters. The calculated quantities have been qualitatively discussed in terms of thermodynamic interactions between the mixing compounds.

Dynamic viscosities, η, densities, ρ, and enthalpies of mixing of binary mixtures containing propylene carbonate + anisole, or + phenetole have been determined at (293.15, 303.15, and 313.15) K and at atmospheric pressure over the whole range of composition. From these results, the deviations in viscosity, Δη, the excess molar volumes, VmE, and the excess molar enthalpies, HmE, have been calculated. Both Δη and VmE are always negative, while positive values have been obtained for HmE. Minima of Δη and VmE and maxima of HmE are the following: −0.248 mPa·s, −0.744 cm3·mol-1, and 347 J·mol-1 for the mixtures propylene carbonate + anisole; −0.248 mPa·s, -0.146 cm3·mol-1, and 766 J·mol-1 for the mixtures propylene carbonate + phenetole. The temperature effect has shown more marked differences for HmE. Results have been correlated using the Redlich−Kister polynomial.

Excess molar enthalpies, H m E , of binary mixtures containing phenetole (ethoxy benzene)+α-pinene, or β-pinene have been determined in the range (288.15–313.15) K, and at atmospheric pressure using a flow microcalorimeter. H m E curves are symmetrical with positive values over the entire concentration range and show higher values for the mixture containing α-pinene (the maximum value for H m E is 1072 J mol −1 ). Only a slight influence of temperature on excess molar enthalpies has been observed for both systems. Experimental results have been correlated using the Redlich–Kister polynomial and the adjustable parameters have been evaluated by least-squares analysis. Results have also been interpreted by an extended modified cell model of Prigogine.

Excess molar enthalpies, H m E , of binary mixtures containing propylene carbonate + six n -alkoxyethanols have been determined using an LKB flow microcalorimeter at 288.15, 298.15, and 313.15 K and at atmospheric pressure. The alkoxyethanols were 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol, and 2-(2-butoxyethoxy)ethanol. From the experimental data, deviations in H m E have been determined and fitted to the Redlich–Kister polynomial to estimate the binary interactions parameters.

Excess molar enthalpies, , and excess molar volumes, , of binary mixtures containing dimethyl carbonate or diethyl carbonate + anisole or + phenetole have been determined at (298.15 and 313.15) K and at atmospheric pressure. Standard deviations have been calculated from correlation of data by the Redlich−Kister polynomial. The calculated quantities have been qualitatively discussed in terms of thermodynamic interactions between the mixing components. Only a slight influence of temperature on the excess properties has been observed.

Excess molar enthalpies and excess molar volumes of diethyl carbonate + some alkoxyethanol mixtures have been determined by an LKB flow microcalorimeter and an Anton Paar density meter as a function of mole fraction of diethyl carbonate at (298.15 and 313.15) K. The alkoxyethanols are 2-methoxyethanol, 2-ethoxyethanol, 2-buthoxyethanol, 2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)ethanol, and 2-(2-butoxyethoxy)ethanol, respectively.

Excess molar enthalpies HmE of binary mixtures containing diethyl carbonate + 1-butanol, + 2-butanol, + 2-methyl-1-propanol, and + 2-methyl-2-propanol have been determined using a flow microcalorimeter in the range (288.15−318.15) K and at atmospheric pressure. All mixtures are strongly endothermic, with maxima of HmE varying from 1900 (mixture containing 1-butanol) to 2550 (mixture containing 2-butanol) J·mol-1. The HmE curves are nearly symmetrical and show values increasing as the temperature increases. Data have been correlated using the Redlich−Kister equation, and experimental results have been qualitatively discussed.

Excess molar enthalpies, , and excess molar volumes, , of propylene carbonate + seven pentanol isomers, namely, 1-, 2-, and 3-pentanol, 2-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-1-butanol, and 3-methyl-2-butanol, have been determined at 298.15 K and at atmospheric pressure using a flow microcalorimeter and a digital densimeter. and values are always positive, with the exception of the volumetric data for the mixture propylene carbonate + 3-methyl-2-butanol, showing a sign inversion of . The Redlich−Kister equation, fitted to the experimental results, provides a satisfactory mathematical representation of and in all mixtures. Results have been qualitatively discussed.

Excess molar enthalpies of binary mixtures containing diethyl carbonate + fourteen n -alkyl alkanoates (six acetates, four propanoates and four butyrates) have been determined at 298.15 K and at atmospheric pressure using an LKB flow microcalorimeter. The experimental data have been fitted to the Redlich-Kister equation to estimate the binary parameters. The results have been qualitatively discussed.

Excess enthalpies have been determined at atmospheric pressure and at 308.15 K over the entire range of composition for binary mixtures containing propylene glycol (PG), dipropylene glycol (DPG), tripropylene glycol (TPG), poly(propylene glycol)-400, -725, -1200, -2000 + dimethyl carbonate (DMC). From the experimetal data, excess enthalpies, H E , and standard deviations in enthalpy, σ ( H E ) have been calculated. The experimental data were fitted to a Redlich–Kister polynomial to obtain the binary adjustable parameters, a k . The H E values are positive over the entire range of composition, decreasing with the increase of the molecular weight of glycols. The mixtures containing polydisperse glycols behave as regular solutions. Conclusions were qualitatively discussed in terms of molecular interactions.

Excess molar enthalpies and excess molar volumes of binary mixtures containing ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, or poly(ethylene glycol)s (PEG200, PEG300, PEG400, and PEG600) + benzyl alcohol were determined at 308.15 K and at atmospheric pressure using a flow microcalorimeter and a digital density meter. Results were fitted to the Redlich-Kister polynomial to estimate the binary interaction parameters. The results are interpreted in terms of molecular interactions between the components.

Excess molar enthalpies, H m E , were determined as a function of molar fraction at 308.15 K and at atmospheric pressure for the binary mixtures containing propylene carbonate with ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, poly(ethylene glycol)-200, poly(ethylene glycol)-300, poly(ethylene glycol)-400, and poly(ethylene glycol)-600. Values of H m E range from a maximum of about 1640 J mol −1 (propylene glycol) to a minimum of about −386 J mol −1 (PEG-600). All mixtures containing monodisperse glycols have positive values of H m E . Also PEG-200 presents a curve of H m E versus x 1 (the molar fraction of glycol, component 1) always positive, whereas PEG-600 presents negative values of the heat of mixing over the whole range of the molar fraction. Finally, PEG-300 and PEG-400 show an inversion of sign of H m E , at about x 1 =0.7 and 0.3, respectively. The experimental data were correlated using the Redlich–Kister polynomial and the adjustable parameters were obtained by the least-squares method. A qualitative discussion have been made in terms of intermolecular H-bonds.

Excess molar enthalpies, H m E , of binary mixtures containing poly(ethylene glycol) (PEG) 200+1,3-dioxolane, PEG 200+1,4-dioxane, PEG 200+oxolane and PEG 200+oxane were determined using a flow microcalorimeter at (288.15, 298.15 and 313.15) K and at atmospheric pressure. The H m E curves are always positive, with maxima varying from 393 J mol −1 (1,3-dioxolane) to 658 J mol −1 (oxolane), showing asymmetrical trends. The effect of the temperature is well marked on the calorimetric data that increase as the temperature is increased. The Redlich–Kister polynomial was used to estimate the binary fitting parameters. Root-mean-square deviations from the regression lines are reported.

Excess molar enthalpies of the 10 binary systems containing ethylbenzene or (2-chloroethyl)benzene+ 2-propanone,+2-butanone,+2-pentanone,+2-octanone and+2-undecanone have been determined using an LKB low microcalorimeter. The experimental data were correlated by means of the Redlich-Kister equation

Determination des enthalpies de melange en phase liquide a 298.15 K, 306.15 K et 313.15 K a l'aide d'une relation, fonction de la composition. Correlation des donnees calorimetriques a l'aide d'une expression empirique de Redlich-Kister