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

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

Physicochemical Properties of Chemicals for Regulatory Purposes Carlos Nieto-Draghi,*,† Guillaume Fayet,‡ Benoit Creton,† Xavier Rozanska, Patricia Rotureau,‡ Jean-Charles de Hemptinne,† Philippe Ungerer, Bernard Rousseau, and Carlo Adamo †IFP Energies nouvelles, 1 et 4 avenue de Bois-Preáu, 92852 Rueil-Malmaison, France ‡INERIS, Parc Technologique Alata, BP2, 60550 Verneuil-en-Halatte, France Materials Design S.A.R.L., 18, rue de Saisset, 92120 Montrouge, France Laboratoire de Chimie-Physique, Universite ́ Paris Sud, UMR 8000 CNRS, Bat̂. 349, 91405 Orsay Cedex, France Institut de Recherche Chimie Paris, PSL Research University, CNRS, Chimie Paristech, 11 rue P. et M. Curie, F-75005 Paris, France Institut Universitaire de France, 103 Boulevard Saint Michel, F-75005 Paris, France

A General Guidebook for the Theoretical Prediction of Physicochemical Properties of Chemicals for Regulatory Purposes.

At present, there is a considerable amount of work devoted to the study of the thermophysical properties of pure ionic liquids, which contrasts with the few data available for their mixtures. One of the most appealing characteristics of ionic liquids is the capability of subtly changing the chemical structure of the cation and anion in order to design appropriate solvents for specific applications. Mixtures of ionic liquids increase enormously this specificity, due to the unlimited combinations that arise from mixing two or more ionic liquids. In this context, the study of the thermophysical properties of these mixtures is revealed as a fundamental task. In this work the viscosities of the ionic liquid binary mixtures with a common ion ([C6mim] + [C2mim])[BF4], ([C6mim] + [C4mim])[BF4], [C4mim]([BF4] + [MeSO4]) and [C4mim]([PF6] + [BF4]) were determined within the temperature range (298.15–308.15) K. The temperature dependence of the viscosity for pure liquids is analyzed by means of the Vogel-Tammann-Fulcher equation and several mixing rules are applied for the mixtures.

Viscosities for Ionic Liquid Binary Mixtures with a Common Ion

The evaluation of phase equilibria and solubility properties through theoretical approaches is a well-known field, where a significant amount of models are able to describe them with a good degree of accuracy. However, the simultaneous calculation of transport properties together with thermodynamic phase properties still remains a challenge, due to the difficulties in describing the behavior of properties like the viscosity of fluids with the same approach. In this work, the free-volume theory (FVT) has been coupled with the soft-SAFT equation for the first time to extend the capabilities of the equation to the calculation of transport properties. The theory has been first tested using simulation data of the viscosity of the Lennard-Jones (LJ) fluid and LJ chains over a wide range of temperature and pressure. Good agreement has been found at all chain lengths, except for some deviations at near-zero density values. Several trends of the viscosity parameters with the length of the chain are identified, all...

Free-Volume Theory Coupled with Soft-SAFT for Viscosity Calculations: Comparison with Molecular Simulation and Experimental Data

The dynamic viscosity η and the density ρ of the associative ternary mixture water+diacetone alcohol+2-propanol have been measured as a function of temperature T (303.15, 323.15, and 343.15 K) and pressure P (≤100 MPa). The experimental results correspond to 698 values of η and ρ. With reference to the 54 values previously published on pure substances and 486 values for three corresponding binaries, the system is globally described by 1188 experimental values for various values of P, T and composition. The results for η are discussed in terms of excess activation energy of viscous flow.

A. Allal

Papers

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

Viscosity and Density at High Pressures in an Associative Ternary

Influence of the Pressure and Temperature on the Viscosity and Density of Binary Water + DAA