Organic Carbonates as Solvents in Synthesis and Catalysis

A new equation of state for the thermodynamic properties of natural gases, similar gases, and other mixtures, the GERG-2008 equation of state, is presented in this work. This equation is an expanded version of the GERG-2004 equation. GERG-2008 is explicit in the Helmholtz free energy as a function of density, temperature, and composition. The equation is based on 21 natural gas components: methane, nitrogen, carbon dioxide, ethane, propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, hydrogen, oxygen, carbon monoxide, water, hydrogen sulfide, helium, and argon. Over the entire composition range, GERG-2008 covers the gas phase, liquid phase, supercritical region, and vapor–liquid equilibrium states for mixtures of these components. The normal range of validity of GERG-2008 includes temperatures from (90 to 450) K and pressures up to 35 MPa where the most accurate experimental data of the thermal and caloric properties are represented to within their accura...

The GERG-2008 Wide-Range Equation of State for Natural Gases and Other Mixtures: An Expansion of GERG-2004

Unperturbed dimensions of stereoregular polymers.- Reinforcement of rubber by carbon black.- Transformations of phenolic antioxidants and the role of their products in the long-term properties of polyolefins.

Properties of polymers

Structure, dynamics and transport properties of microemulsions

http://path.web.ua.pt/file/fped0700500r1.pdf

A group contribution method for viscosity estimation of ionic liquids

A free-volume and friction viscosity model is presented versus pressure and temperature, valid for both gaseous and dense fluids. This model involves only three adjustable parameters for each pure compound. It is able to represent the gas-liquid transition and the behavior in the supercritical conditions. The model has been successfully applied to methane (885 data points for 0.01< or =P< or =200 MPa and 90.7< or =T< or =600 K) and to propane (1085 data points for 0.01< or =P< or =200 MPa and 90< or =T< or =600 K) in the gaseous and dense states (average absolute deviation is 2.59% for methane and 2.50% for propane, with maximum deviation of 14.8% for methane and 9.19% for propane). It has also been applied to hexane, octane, dodecane, benzene, trans-decaline, and 2,2-dimethylpropane (903 data points) in a large pressure range (up to 505.5 MPa). Considering these compounds the maximum deviation is 19.5% (for octane) and the average deviation is 3.51% in the worst case (dodecane, which has data points up to 501.6 MPa).

Free-volume viscosity model for fluids in the dense and gaseous states.

The viscosity and density of four pure liquid compounds (dimethyl carbonate, diethyl carbonate, triethylene glycol dimethyl ether, and tetraethylene glycol dimethyl ether) were measured at several temperatures between 283.15 and 353.15 K. The density measurements were performed up to 60 MPa with an uncertainty of 1×10−4g·cm−3. The viscosity at atmospheric pressure was measured with an Ubbelohde-type glass capillary tube viscometer with an uncertainty of ±1%. At pressures up to 100 MPa the viscosity was determined with a falling ball viscometer with an uncertainty of ±2%. The density (410 experimental values) and viscosity data (184 experimental values) were fitted to several correlation equations.

High-Pressure Measurements of the Viscosity and Density of Two Polyethers and Two Dialkyl Carbonates

New density data for diethyl adipate (DEA) over 12 isotherms [(293.15 ≤ T ≤ 403.15) K] and 15 isobars [(0.1 ≤ p ≤ 140) MPa] are reported. This paper presents also the calibration procedure we propose for a new experimental equipment. Data reliability has been verified over the pressure and temperature experimental intervals by comparing our experimental results for toluene and 1-butanol with previous literature data. A total of 732 experimental data points have been measured in the framework of this work. The experimental uncertainty is estimated to be ± 0.5 kg·m−3 (around 0.05 %). The pressure and temperature dependencies of diethyl adipate densities were accurately represented by the Tammann−Tait equation with standard deviations of 0.3 kg·m−3. These data were used to analyze the isothermal compressibility and the isobaric thermal expansivity for this fluid.

Density of diethyl adipate using a new vibrating tube densimeter from (293.15 to 403.15) K and up to 140 MPa. calibration and measurements

This article presents a model based on the free volume concept, which describes the variations of dynamic viscosity and density versus temperature and pressure for the dense fluids (density > 200 kg · m−3). This model involves 6 constants for each pure compound: 3 for viscosity and 4 for density (1 constant is common to both quantities). Moreover if the viscosity and the density are known at a pressure and temperature of reference, it is sufficient to use 4 constants per pure compound. If the density is assumed to be known the model fits the viscosity data with an average absolute deviation of 3.8% for 3297 data corresponding to 41 very different pure compounds (alkanes, alkylbenzenes, cycloalkanes, alcohols, carbon dioxide, refrigerants). If the pressure is lower than 110MPa the average absolute deviation is 2.8% for viscosity (2977 points). The model gives also good results for water (3.6%). If the density is unknown, for pressures lower than 110MPa the model represents viscosity with an averag...

A New Free Volume Model for Dynamic Viscosity and Density of Dense Fluids Versus Pressure and Temperature

In this work, we have tested the efficiency of two scaling approaches aiming at relating shear viscosity to a single thermodynamic quantity in dense fluids, namely the excess entropy and the thermodynamic scaling methods. Using accurate databases, we have applied these approaches first to a model fluid, the flexible Lennard-Jones chain fluid (from the monomer to the hexadecamer), then to real fluids, such as argon and normal alkanes. To enlarge noticeably the range of thermodynamics conditions for which these scaling methods are applicable, we have shown that the use of the residual viscosity instead of the total viscosity is preferable in the scaling procedures. It has been found that both approaches, using the adequate scaling, are suitable for the Lennard-Jones chain fluid model for a wide range of thermodynamic conditions whatever the chain length when scaling law exponents and prefactors are adjusted for each chain length. Furthermore, these results were found to be well respected by the corresponding real fluids.

Christian Boned

Papers

Free-volume viscosity model for fluids in the dense and gaseous states.

High-Pressure Measurements of the Viscosity and Density of Two Polyethers and Two Dialkyl Carbonates

Density of diethyl adipate using a new vibrating tube densimeter from (293.15 to 403.15) K and up to 140 MPa. calibration and measurements

A New Free Volume Model for Dynamic Viscosity and Density of Dense Fluids Versus Pressure and Temperature

Scaling of the viscosity of the Lennard-Jones chain fluid model, argon, and some normal alkanes.