Dielectric studies of novel polymeric systems

Simple item page
dc.contributor.authorNorris, Ann Marie Walstromen
dc.contributor.committeechairWard, Thomas C.en
dc.contributor.committeememberMcGrath, James E.en
dc.contributor.committeememberWightman, James P.en
dc.contributor.committeememberGibson, Harry W.en
dc.contributor.committeememberBrinson, Halbert F.en
dc.contributor.departmentMaterials Engineering Scienceen
dc.date.accessioned2015-06-24T13:35:29Zen
dc.date.available2015-06-24T13:35:29Zen
dc.date.issued1987en
dc.description.abstractThis work combines many characterization techniques in an effort to enhance understanding of molecular motions of polymers and. how they are influenced by' structure. The primary characterization method was dielectric spectroscopy which utilizes an AC electric field as the stress field. A variety of new, well controlled polymeric systems were studied. The first series included a number of radial starblock copolymers, styrene/isoprene, t-butyl- styrene/isoprene, and t-butyl-styrene/butadiene. These ABA copolymers consisted of hard and soft blocks, with the soft block comprising 75% by weight. The effect of microstructure of the soft block, casting solvent, hydrogenation, and chemical composition of the hard block were some of the variables studied. The amount of phase separation and the molecular motions occurring will be influenced by these parameters. Hydrogenation of the soft block increased the phase separation. Another system investigated included some stereospecific poly(alkyl methacrylates) which were synthesized anionically. In this series the alkyl group was systematically changed in order to study the effects of the bulkiness of the substituent and the tacticity on the a and ß transitions. The ß transition associated with side chain rotations was only observed in the case of the methyl and ethyl substituents. The Havriliak-Negami data analysis was used to evaluate the breadth and the skewness of the distribution of relaxation times. Finally, some high temperature thermoplastic polymers were evaluated with dielectric spectroscopy. The effect of the backbone composition, moisture, and fillers on the β transition was looked at. These studies showed that moisture and fillers play an important role on the magnitude and temperature of the observed β transition.en
dc.description.degreePh. D.en
dc.format.extentxii, 148 leavesen
dc.format.mimetypeapplication/pdfen
dc.identifier.urihttp://hdl.handle.net/10919/53656en
dc.language.isoen_USen
dc.publisherVirginia Polytechnic Institute and State Universityen
dc.relation.isformatofOCLC# 18160929en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V856 1987.N676en
dc.subject.lcshDielectric relaxationen
dc.subject.lcshBlock copolymersen
dc.subject.lcshPolymersen
dc.titleDielectric studies of novel polymeric systemsen
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

Files

Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
LD5655.V856_1987.N676.pdf
Size:
3.77 MB
Format:
Adobe Portable Document Format
Download

Collections

Doctoral Dissertations