Dilute solution studies of molecular weight distributions of nitrocellulose, modified lignins and PMMA graft polymers

dc.contributor.authorSiochi, Emilie J.en
dc.contributor.committeechairWard, Thomas C.en
dc.contributor.committeememberMcGrath, James E.en
dc.contributor.committeememberWilkes, Garth L.en
dc.contributor.committeememberSanzone, Georgeen
dc.contributor.committeememberWightman, James P.en
dc.contributor.departmentMaterials Engineering Scienceen
dc.date.accessioned2015-07-10T20:00:04Zen
dc.date.available2015-07-10T20:00:04Zen
dc.date.issued1989en
dc.description.abstractDilute solution properties of three difficult-to-analyze macromolecular systems were investigated and clarified. Two were notorious for having highly time-in-solution dependent properties, nitrocellulose and lignin, while the third was an ideal model branched methacrylate polymer with which to examine unanswered questions in polymer hydrodynamic behavior. Gel permeation chromatography with a differential viscosity detector (GPC/DV) was employed to study the dilute solution properties of various polymers, specifically their absolute molecular weight distributions and hydrodynamic behavior. The study was divided into three parts. The first part focused on the time dependent change in molecular weight of nitrocellulose. Samples having 12.58% and 13.5% levels of nitration were investigated in THF and EtOAc. GPC/DV, LALLS, FT-IR and intrinsic viscosity experiments revealed that the materials existed as associated molecules in solution which decreased in molecular weight upon storage to extents dependent on the solvent. The second part was an examination of the hydrodynamic behavior of hydroxypropylated lignins using GPC/LALLS/DV and VPO. These materials were found to increase in molecular weight upon storage in solution due to association. Special precautions had to be taken in running experiments to obtain the correct molecular weights and molecular weight distributions. The last part involved a fundamental study of PMMA-g-PMMA's having similar molecular weights but containing different levels of branching. Variable temperature GPC/LALLS/DV was employed to obtain molecular weight distributions, branching parameters, average chain dimensions and information on the hydrodynamic behavior of these branched systems. Samples containing up to 40% of long chain branching were found to obey the universal calibration analytic scheme of GPC.en
dc.description.degreePh. D.en
dc.format.extentxvii, 282 leavesen
dc.format.mimetypeapplication/pdfen
dc.identifier.urihttp://hdl.handle.net/10919/54423en
dc.language.isoen_USen
dc.publisherVirginia Polytechnic Institute and State Universityen
dc.relation.isformatofOCLC# 20139846en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V856 1989.S563en
dc.subject.lcshPolymers -- Viscosityen
dc.subject.lcshGel permeation chromatographyen
dc.titleDilute solution studies of molecular weight distributions of nitrocellulose, modified lignins and PMMA graft polymersen
dc.typeDissertationen
dc.type.dcmitypeTexten
thesis.degree.disciplineMaterials Engineering Scienceen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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