Diffusion And Equilibrium Measurements In Polymer-Solvent Systems By Inverse Gas Chromatography Method

Diffusion And Equilibrium Measurements In Polymer-Solvent Systems By Inverse Gas Chromatography Method
Author :
Publisher :
Total Pages : 180
Release :
ISBN-10 : OCLC:417646452
ISBN-13 :
Rating : 4/5 (52 Downloads)

Synopsis Diffusion And Equilibrium Measurements In Polymer-Solvent Systems By Inverse Gas Chromatography Method by : Hülya Eser

In this study, thermodynamic properties, namely retention volume, infinitely dilute weight fraction activity coefficient, Flory- Huggins interaction parameter, solubility parameters of solute and polymer, partition coefficient and diffusion coefficients of the various solvents in poly (methyl methacrylate co butyl methacrylate) (PMMA co BMA) and poly (lactide co glycolide) (PLGA) at infinite dilution of the solvent have been determined by inverse gas chromatography (IGC). In this technique, a small amount of the solvent was injected into the capillary column and its retention time was measured and used to calculate several polymer-solvent interaction parameters which are mentioned above. The solutes used in this study were methanol, ethanol, propanol, butanol, methyl acetate, ethyl acetate, propyl acetate, dichloromethane, trichloromethane, acetone, methyl methacrylate, butyl methacrylate, water for PMMA co BMA and acetone, dichloromethane, trichloromethane, ethyl acetate, ethyl alcohol, tetrahydrofuran, water for PLGA. The glass transition temperature of the polymers were determined as 106 0C and 42 0C for PMMA co BMA and PLGA respectively by differential scanning calorimetry. Experiments were performed in the range of 150-200 0C for PMMA co BMA and 80-120 0C for PLGA which are above the glass transition temperature of the polymer. The thermodynamic results, obtained from the experiments, indicated that trichloromethane and dichloromethane were the most suitable solutes among all the solvents studied for both of the polymers. The partition (K) and diffusion coefficients (Dp) of various solvents at infinite dilution of the solvent were calculated by using the model developed by Pawlisch et al. (1987). The optimum K and Dp values that best fit the data were found and the model predicted experimental data very well. In summary, IGC method is a powerful tool for the determination of thermodynamic and diffusion properties of solvent in polymer at infinite dilution of the solvent. Vrentas- Duda free volume theory was used to correlate the diffusion data and to investigate the effect of solvent size on diffusion process. The theory has shown to correlate diffusion data above the glass transition temperature very well for the PMMA-co-BMA .solvent system.

CRC Handbook of Enthalpy Data of Polymer-Solvent Systems

CRC Handbook of Enthalpy Data of Polymer-Solvent Systems
Author :
Publisher : CRC Press
Total Pages : 638
Release :
ISBN-10 : 0849393612
ISBN-13 : 9780849393617
Rating : 4/5 (12 Downloads)

Synopsis CRC Handbook of Enthalpy Data of Polymer-Solvent Systems by : Christian Wohlfarth

The CRC Handbook of Enthalpy Data of Polymer-Solvent Systems presents data that is as essential to the production, process design, and use of polymers as it is to understanding the physical behavior and intermolecular interactions in polymer solutions and in developing thermodynamic polymer models. Providing an all-encompassing collection of current enthalpy data for all types of polymer solutions, this handbook is a ready companion with Christian Wohlfarth’s previously published handbooks of thermodynamic data for copolymer solutions, aqueous polymer solutions, and polymer solutions at elevated pressures, which contain only a small amount of enthalpic data in comparison to the data presented here. This volume contains 1770 data sets that include enthalpies of mixing and dilution for the entire concentration range as well as partial enthalpies of mixing and solution at infinite dilution. Special appendices allow scientists to access specific systems and data easily. The CRC Handbook of Enthalpy Data of Polymer-Solvent Systems is a practical, one-stop resource that allows polymer chemists, biochemists, chemical engineers, materials scientists, and physical chemists involved in both industrial and laboratory processes to quickly retrieve relevant information as needed.

Polymer Thermodynamics by Gas Chromatography

Polymer Thermodynamics by Gas Chromatography
Author :
Publisher : Elsevier
Total Pages : 212
Release :
ISBN-10 : 9780444597434
ISBN-13 : 0444597433
Rating : 4/5 (34 Downloads)

Synopsis Polymer Thermodynamics by Gas Chromatography by : R. Vîlcu

This book presents direct and inverse gas chromatography as a powerful tool for determining a great number of thermodynamic properties and quantities for micro- and especially for macromolecular substances. In order to ensure the continuity and clarity of the presentation, the book first considers some frequently used concepts of chromatography with a mobile gas phase, i.e. the mechanism of separation, retention parameters and the theories of gas chromatography. The employment of this technique as an important method of studying solutions through the most representative statistical models is also discussed. The thermodynamics of direct gas chromatography, as applied to dissolution, adsorption and vaporization underlies the thermodynamic treatment of inverse gas chromatography. The most extensive chapter of the book is devoted to the thermodynamics of inverse gas chromatography and deals with a number of important topics: phase transitions in crystalline-amorphous polymers and liquid crystals, glass transitions, other second order transitions in polymers, the determination of diffusion coefficients, the segregation of block copolymers and other applications.This book is intended for those specialists in research and industry who are concerned with the modification and characterization of polymers, with establishing polymer applications, and with the processing of polymers. It will also be useful to students and specialists interested in the physico-chemical basis of the phenomena involved in gas chromatography in general and its inverse variant in particular.

Handbook of Polymer Solution Thermodynamics

Handbook of Polymer Solution Thermodynamics
Author :
Publisher : John Wiley & Sons
Total Pages : 194
Release :
ISBN-10 : 9780470938225
ISBN-13 : 0470938226
Rating : 4/5 (25 Downloads)

Synopsis Handbook of Polymer Solution Thermodynamics by : Ronald P. Danner

Created for engineers and students working with pure polymers and polymer solutions, this handbook provides up-to-date, easy to use methods to obtain specific volumes and phase equilibrium data. A comprehensive database for the phase equilibria of a wide range of polymer-solvent systems, and PVT behavior of pure polymers are given, as are accurate predictive techniques using group contributions and readily available pure component data. Two computer programs on diskettes are included. POLYPROG implements procedures given for prediction and correlation for specific volume of pure polymer liquids and calculation of vapor-liquid equilibria (VLE) of polymer solutions. POLYDATA provides an easy method of accessing the data contained in the many databases in the book. Both disks require a computer with a math coprocessor. This handbook is a valuable resource in the design and operation of many polymer processes, such as polymerization, devolatilization, drying, extrusion, and heat exchange. Special Details: Hardcover with Disks. Special offer: Purchase this book along with X-131, Handbook of Diffusion and Thermal Properties of Polymers and Polymer Solutions and receive a 20 percent discount off the list or member price.