A statistical mechanical non-lattice coordination theory to describe the solution thermodynamics of polymer mixtures.

Persistent Link:
http://hdl.handle.net/10150/186340
Title:
A statistical mechanical non-lattice coordination theory to describe the solution thermodynamics of polymer mixtures.
Author:
Ochs, Leonard Ryder.
Issue Date:
1993
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
A theoretical model has been developed to advance the study of the thermodynamics of highly concentrated binary polymer solutions. This statistical mechanical theory was developed to allow the modeling of the molar Gibbs and Helmholtz free energies of mixing as well as the standard derived functions, such as the solvent and solute activities, and the molar enthalpies and entropies of mixing. Three major results have been generated from this work: (1) The polymer/solvent interactions can be partitioned into a coordination term, which leads to a configurational entropy, and an interaction energy of mixing term, which leads to the standard enthalpy of mixing; (2) The temperature dependence of the enthalpy of mixing yields an interaction energy of mixing which incorporates an additional entropy of mixing which is present for all types of systems, even athermal mixtures; and (3) The theory enables the use of experimentally obtained enthalpies of mixing to be used directly in the prediction of solvent activities, and experimentally determined solvent activities to be used as a predictor of the enthalpies of mixing without differentiating the experimental data. The theory was tested on fifteen binary systems. These systems had a range of physical property characteristics, from mixtures which can be considered almost ideal, to highly non-ideal athermal polymer solutions, to aqueous polymer solutions. The studied systems were; benzene/cyclopentane, benzene/cyclohexane, benzene/biphenyl, benzene/diphenylmethane, benzene/1,2-diphenylethane, cyclohexane/bicyclohexyl, n-hexane/n-hexadecane, toluene/polystyrene, chloroform/polystyrene, methylethylketone/polystyrene, cyclohexane/polystyrene, benzene/polypropylene glycol, benzene/polyethylene glycol, water/glucose, and water/polyethylene glycol. Parameters for each of these systems and components are tabulated. The experimental solvent activity data are graphed with the regression lines, and the experimental enthalpy of mixing data are graphed with the curves predicted from the solvent activity parameters. The average relative error of fit for the regression of the solvent activity data up to a polymer volume fraction of about 0.85 is less than ±0.0035, while for the entire solvent activity data set it is ±0.025. The average relative error of fit for the molar enthalpy of mixing predictions (excluding the water/PEG data) is less than ±0.005.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Dissertations, Academic.; Chemistry, Physical and theoretical.; Chemical engineering.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemical Engineering; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Cabezas, Heriberto, Jr.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleA statistical mechanical non-lattice coordination theory to describe the solution thermodynamics of polymer mixtures.en_US
dc.creatorOchs, Leonard Ryder.en_US
dc.contributor.authorOchs, Leonard Ryder.en_US
dc.date.issued1993en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractA theoretical model has been developed to advance the study of the thermodynamics of highly concentrated binary polymer solutions. This statistical mechanical theory was developed to allow the modeling of the molar Gibbs and Helmholtz free energies of mixing as well as the standard derived functions, such as the solvent and solute activities, and the molar enthalpies and entropies of mixing. Three major results have been generated from this work: (1) The polymer/solvent interactions can be partitioned into a coordination term, which leads to a configurational entropy, and an interaction energy of mixing term, which leads to the standard enthalpy of mixing; (2) The temperature dependence of the enthalpy of mixing yields an interaction energy of mixing which incorporates an additional entropy of mixing which is present for all types of systems, even athermal mixtures; and (3) The theory enables the use of experimentally obtained enthalpies of mixing to be used directly in the prediction of solvent activities, and experimentally determined solvent activities to be used as a predictor of the enthalpies of mixing without differentiating the experimental data. The theory was tested on fifteen binary systems. These systems had a range of physical property characteristics, from mixtures which can be considered almost ideal, to highly non-ideal athermal polymer solutions, to aqueous polymer solutions. The studied systems were; benzene/cyclopentane, benzene/cyclohexane, benzene/biphenyl, benzene/diphenylmethane, benzene/1,2-diphenylethane, cyclohexane/bicyclohexyl, n-hexane/n-hexadecane, toluene/polystyrene, chloroform/polystyrene, methylethylketone/polystyrene, cyclohexane/polystyrene, benzene/polypropylene glycol, benzene/polyethylene glycol, water/glucose, and water/polyethylene glycol. Parameters for each of these systems and components are tabulated. The experimental solvent activity data are graphed with the regression lines, and the experimental enthalpy of mixing data are graphed with the curves predicted from the solvent activity parameters. The average relative error of fit for the regression of the solvent activity data up to a polymer volume fraction of about 0.85 is less than ±0.0035, while for the entire solvent activity data set it is ±0.025. The average relative error of fit for the molar enthalpy of mixing predictions (excluding the water/PEG data) is less than ±0.005.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectDissertations, Academic.en_US
dc.subjectChemistry, Physical and theoretical.en_US
dc.subjectChemical engineering.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemical Engineeringen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairCabezas, Heriberto, Jr.en_US
dc.contributor.committeememberBaygents, James C.en_US
dc.contributor.committeememberGuzman, Robertoen_US
dc.contributor.committeememberBarfield, Michaelen_US
dc.contributor.committeememberSalzman, Williamen_US
dc.identifier.proquest9408375en_US
dc.identifier.oclc720351687en_US
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