A VSE equation of state for liquids. V. Poly(tetrafluoroethylene), 600–725 K

Our volume–entropy–energy (VSE) equation of state for liquids, first proposed in 1973 for use with low molecular weight homogeneous liquids, is here applied for the first time to a high molecular weight liquid that is heterogeneous in molecular weight, namely, a molten polymer. Four thermo-dynamic quantities, T, s, c_p, and ε are calculated over the range of 600–725 K at ambient pressure and are compared with experimental values, with excellent results. The grand average of the standard percentage errors (S.P.E.) for the 24 points is 0.1100%.     

An equation of state for liquids

A comparatively simple and accurate equation of state has been developed for the liquid state. The proposed equation has the form where K and q are constants dependent on temperature. The equation is tested for validity against P-V-T data for aldehydes obtained in the course of this investigation. Literature data on alkanes, alcohols, and water were also utilized to confirm the validity of the equation. A critical comparison of the proposed equation with the Hudleston equation reveals the former to yield more satisfactory prediction of P-V-T behavior of liquids.     

A new four-parameter cubic equation of state for mixtures. Vapor–liquid equilibrium calculations

A new four-parameter cubic equation of state has been recently developed and has accurately reproduced the thermodynamic properties of pure substances including polar fluids. In this work we apply the equation to vapor-liquid equilibrium calculations through the introduction of different mixing rules. Various classes of mixtures are investigated at low pressures as well as at high pressures. The calculated results show that the equation with the Huron-Vidal mixing rules offers better correlations for all types of systems over a wide range of temperature and pressure.     

Pressure–volume–temperature relationships for polymeric liquids: A review of equations of state and their characteristic parameters for 56 polymers

A review of theoretical equations of state for polymer liquids is presented. Characteristic parameters for six equations of state, as well as parameters for the empirical Tait equation, are given for 56 polymers where pressure–volume–temperature (PVT) data over a wide range of conditions could be found in the literature. New PVT data are presented for four polymers: poly(epichlorohydrin), poly(?-caprolactone), poly(vinyl chloride), and atactic polypropylene. All six equations of state provide adequate fits of the experimental specific volume data for the 56 polymers in the low pressure range (up to 500 bar). The modified cell model of Dee and Walsh, the Simha–Somcynsky hole theory, the Prigogine cell model, and the semiempirical model of Hartmann and Haque, were all found to provide good fits of polymer liquid PVT data over the full range of experimental pressures. The Flory–Orwoll–Vrij and the Sanchez–Lacombe lattice–fluid equations of state were both significantly less accurate over the wider pressure range. © 1993 John Wiley & Sons, Inc.     

New isotherm regularity and an equation of state for gases and liquids

In this paper an isotherm regularity has been introduced for gases and liquids based on intermolecular potential energy. The experimental data has been used to demonstrate the validity of the regularity. A non-linearity relationship exists between (Z ? 1)v³ and ρ for all isotherms of liquids and gases. The basis for this regularity is intermolecular potential which is a modified Lennard–Jones potential (9, 6, 3) for repulsive, dispersion, dipole–dipole and longer-ranged interactions. The isotherm regularity is equivalent to a virial-like EOS for which the parameters of the isotherm form the corresponding second, third and fourth virial-like coefficients. The equation of state is simple and ready to use. The parameters of equation of state are determined by fitting isothermal regularity to experimental data. The new equation of state provides excellent results in homogenous gas and homogeneous liquids region to very high pressures while its predictions in gas-liquid transition have more deviations. Densities of 1828 data points of 21 components have been calculated over the entire range of data with a maximum pressure of 1000 MPa. The average absolute deviation between calculated and experimental densities for gases, liquids and gas-liquid transition region are 0.06%, 0.03% and 0.90%, respectively.     

Measurement of thermophysical properties of polyester cured with styrene in the range 300–450 K

A pulse method for the simultaneous determination of thermal diffusivity, α, specific heat capacity, C_p, and thermal conductivity, λ, are measured for a series of curing of polyester and styrene in the presence of 10, 20, and 30% carbon black in the temperature range 300–450 K. The results show a dependence of the above-mentioned properties on temperature and composition. The mechanism of heat transfer through the specimens is also discussed. © 1993 John Wiley & Sons, Inc.     

Surface and interfacial tension of polymer liquids –a review

The surface tension of a polymer liquid is a property of considerable practical importance. Within the past decade the experimental difficulties in accurately measuring the surface tension of viscous polymer melts have been overcome, and a considerable body of data is now available. This review discusses the measurement techniques which have proved useful, the results which have been obtained, and theoretical approaches which have been applied to them. A tabulation of surface and interfacial tension values which have been published up to mid-1971 is included.     

Group contribution lattice fluid equation of state for CO2–ionic liquid systems: An experimental and modeling study

The group contribution lattice fluid equation of state (GCLF EOS) was first extended to predict the thermodynamic properties for carbon dioxide (CO₂)–ionic liquid (IL) systems. The group interaction parameters of CO₂ with IL groups were obtained by means of correlating the exhaustively collected experimental solubility data at high temperatures (above 278.15 K). New group parameters between CO₂ and IL groups were added into the current parameter matrix. It was verified that GCLF EOS with two kinds of mixing rules could be used for predicting the CO₂ solubility in ILs, and volume expansivity of ILs upon the addition of CO₂, as well as identifying the new structure–property relation. Moreover, it is the first work on the measurement of the solubility of CO₂ in ILs at low temperatures (below 278.15 K), manifesting the applicability of predictive GCLF EOS over a wider temperature range. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4399–4412, 2013     

A semi-empirical equation of state for fluids

An eight parameter equation of state for calculating the volumetric behaviour of fluids has been derived on the basis of three main assumptions:—The thermodynamic equation of state P +(?E|?V)_T = T(?S|?V)_T as a general theoretical frame.—The Maxwell relation (?P|?T)_V = (?S|?V)_T as a thermodynamic link between the empirical parameters of the equation.—A Van der Waals-type potential for attractive forces.The new equation has been applied to ten fluids, five polar and five apolar, in an experimental range up to three times the critical density and up to five times the critical temperature.The new equation compares favorably in accuracy with the BWR equation.     

A generalized equation of state for polymers

A simple, generalized equation of state has been developed that describes the pressure–volume–temperature behavior of both addition and condensation polymers. Use of the equation requires only that the polymer's glass temperature and density at 25°C. and one atmosphere be known. The equation applies to both amorphous and crystalline polymers for pressures up to 10,000 atm. It also appears to hold for copolymers. Polymer glass temperatures can also be estimated with the equation.     

Prediction of thermodynamic properties of polymeric liquids using a new equation of state

In this paper, we have used a simple equation of state (EoS) to predict the density for polymeric liquid mixtures at different temperatures, pressures, and compositions. The excess molar volumes of these mixtures have been also calculated using this equation of state. Also, we have computed isothermal compressibility. A wide comparison with experimental data has been made for each thermodynamic property. The values of statistical parameters between experimental and calculated properties show the ability of this equation of state in reproducing and predicting different thermodynamic properties for studied polymeric mixtures.     

4–Hydroxy–3–arylamino–l, 8–naphthalimides and 3–(and 4–) hydroxy–2–(and 5–) arylamino–7H–bcnzimidazo–(2, l–a)benz(d,e)isoquinolin–7–ones. Red dyes for synthetic–polymer fibres

4–Hydroxy–1, 8–naphthalimides and the isomer mixtures of'3–and 4–hydroxy–7 H–benzimidazo–(2, l–a)–benz(d, e)–isoquinolin–7–ones were coupled with diazotised arylamines to yield orange–red to bluish–red dyes having good coloration properties and excellent fastness to light on polyester fibres. Structure–property relationships in the dyes are discussed with respect to the nature of the substituents in the imide, imidazole and arylazo moieties.     

New Intermediates and Dyes for Synthetic–polymer Fibres 4–(4–Methoxyanilino)–3–nitro–l, 8–naphthalimides

The synthesis of a series of 4–(4–methoxyanilinoj–3–nitro–1, 8–naphthalimides by condensation of amines with 4–(4–methoxyanilino)–3–nitronaphthalene–l, 8–dicarboxylic anhydride, and also by condensation of 4–halogeno–3–nitro–1, 8–naphthalimides with 4–methoxyaniline is described. They dye synthetic–polymer fibres, particularly polyesters, deep orange of excellent fastness properties. In presence of strong bases, e. g. 3–aminopropan–l–ol, the 4–arylamino group is replaced, giving a series of yellow dyes. A method is described for preparing the dyes without isolation of intermediate stages.     

The Photofading of 1 –Arylazo–2–naphthols in Solution.

1–(Substituted phenylazo)–2–naphthols with a nitro group positioned para– or ortho– to the azo group, show anomalous photofading behaviour in methanol, i. e., their fastness to light is very much lower than that of similar compounds. On the other hand, although 1 –(o–nitrophenylazo)–2–naphthol (II) in alcoholic solvents faded to give similar products via photooxidative and/or photoreductive reactions, little photoreduction of the nitro group was detected, and the rate of photofading of II was lower than that of la. The contribution of intramolecular interaction, such as intramolecular bifurcated hydrogen bonding, involving the o–nitro group, azo group and o–hydroxy group of 1–(o–nitrophenylazo)–2–naphthol, are also discussed. Photochemical reaction of 1–(p–nitrophenylazo)–2–naphthol (la) in methanol, ethanol or 2–propanol produces not only oxidative but also reductive products, while photochemical reaction of la in acetone gives only oxidative products. From these results and earlier observations, it is suggested that the anomalous photofading of la is a substrate–specific phenomenon, and may be caused by photo–reduction of the nitro and azo groups to amino groups by the substrate, instead of the normal photo–oxidation of the hydrazone tautomer by singlet oxygen.