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dc.contributor.authorLiu, Kunen_US
dc.date.accessioned2014-03-14T20:19:21Z
dc.date.available2014-03-14T20:19:21Z
dc.date.issued2007-11-15en_US
dc.identifier.otheretd-11292007-172805en_US
dc.identifier.urihttp://hdl.handle.net/10919/29787
dc.description.abstractMISCIBILITY, VISCOSITY, DENSITY, AND FORMATION OF POLYMERS IN HIGH-PRESSURE DENSE FLUIDS Kun Liu (Abstract) This thesis is an experimental investigation of the phase behavior, volumetric properties, and viscosity of poly (methyl methacrylate) (PMMA), poly (ε-caprolactone) (PCL) and their blends. Homopolymerization and copolymerizations of methyl methacrylate (MMA) and 2-methylene-1,3-dioxepane (MDO) in mixtures of acetone + CO2 have also been explored. The viscosities and densities of acetone + CO2 mixtures were measured in the temperature range 323-398 K at pressures up to 35 MPa. This is the first study in which viscosity of acetone + CO2 mixtures have been measured and the mixtures have been evaluated as solvents for PCL. It is shown that PCL can be readily dissolved in these fluid mixtures at modest pressures even at high carbon dioxide levels. Investigations have been conducted over a temperature range from 323 to 398 K at pressures up to 50 MPa for polymer concentrations up to 20 wt %, and CO2 concentrations up to 60 wt %. It is shown that in these mixtures PCL is dissolved at pressures that are much lower than the pressures reported for miscibility in the mixtures of carbon dioxide with other organic solvents. It is shown that PMMA also readily dissolves at modest pressures. Blends of PMMA and PCL require higher pressures than for the individual polymers for complete miscibility. Free-radical polymerizations of MMA in acetone at 343 K were followed using in-situ measurements of viscosity and density at different pressures from 7- 42 MPa. This is the first time viscosity has been used as a real-time probe of high pressure polymerizations. Two distinct kinetic regimes were identified. Homopolymerizations of MDO were conducted in carbon dioxide at 323 and 343 K at pressures up to 42 MPa. For the first time it is shown that high molecular weight PCL can be produced from MDO in high pressure CO2. Ring-opening free-radical copolymerizations of MDO with MMA, styrene and acrylonitrile were conducted for the first time in carbon dioxide and have been shown to lead to polymers with high molecular weights.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartAcknowledgements.pdfen_US
dc.relation.haspartChapter1.pdfen_US
dc.relation.haspartChapter7.pdfen_US
dc.relation.haspartChapter8.pdfen_US
dc.relation.haspartChapter10.pdfen_US
dc.relation.haspartChapter12.pdfen_US
dc.relation.haspartChapter9.pdfen_US
dc.relation.haspartAttributionPage.pdfen_US
dc.relation.haspartChapter6.pdfen_US
dc.relation.haspartListofTables.pdfen_US
dc.relation.haspartChapter4.pdfen_US
dc.relation.haspartReferences.pdfen_US
dc.relation.haspartTableofContents.pdfen_US
dc.relation.haspartChapter5.pdfen_US
dc.relation.haspartAbstract.pdfen_US
dc.relation.haspartChapter3.pdfen_US
dc.relation.haspartVita.pdfen_US
dc.relation.haspartPreface.pdfen_US
dc.relation.haspartChapter2.pdfen_US
dc.relation.haspartListofFigures.pdfen_US
dc.relation.haspartChapter11.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectHigh pressureen_US
dc.subjectAcetoneen_US
dc.subjectCarbon dioxideen_US
dc.subjectSupercritical fluidsen_US
dc.subjectPolymer solutionsen_US
dc.subjectPoly (methyl methacrylate)en_US
dc.subjectBlendingen_US
dc.subjectViscosityen_US
dc.subjectPolymerizationen_US
dc.subjectPoly (ε-caprolactone)en_US
dc.titleMiscibility, Viscosity, Density, and Formation of Polymers in High-Pressure Dense Fluidsen_US
dc.typeDissertationen_US
dc.contributor.departmentChemical Engineeringen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineChemical Engineeringen_US
dc.contributor.committeechairKiran, Erdogan R.en_US
dc.contributor.committeememberDavis, Richey M.en_US
dc.contributor.committeememberMarand, Evaen_US
dc.contributor.committeememberLong, Timothy E.en_US
dc.contributor.committeememberDeck, Paul A.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-11292007-172805/en_US
dc.date.sdate2007-11-29en_US
dc.date.rdate2008-01-18
dc.date.adate2008-01-18en_US


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