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AuthorBoger, Andreasdc.contributor.author
Date of accession2016-03-14T11:54:30Zdc.date.accessioned
Available in OPARU since2016-03-14T11:54:30Zdc.date.available
Year of creation2003dc.date.created
AbstractThe subject of this thesis is the examination of the properties of polypropylene (PP) with different amount of isotacticity. The presented measurements show the large range of properties of polypropylene: lasting from plastic, semi-crystalline to highly elastic X-ray-amorphous. The lower the crystallinity, the higher the elasticity of the samples. Thus, the x-ray-amorphous sample achieves a complete resetting of the strain after the first drawing cycle. The stress-strain behavior of the sample was described by the Van der Waals model for polymers. By the dynamic-mechanical measurements the complex compliance was determined in dependence of the temperature, frequency and shear amplitude. Here the observed phase transitions could be correlated with the DSC measurements. Thereby, the amorphous X-ray sample turns out to have a great capability as rubber material; its rubber plateau extending over a temperature range of 150K. In order to decide which processes are responsible for these transitions, temperature dependent WAXS and SAXS measurements were performed. For this purpose, setups at the polymerbeamline in the HASYLAB at DESY were realized, which permitted efficient measurement periods with an accuracy comparable to Guiniertechnique. The high accuracy of +/-0.5 Grad in the scattering angle also allowed for a reflex analysis, by which the crystallite size was determined in dependence of the temperature and the crystal modifications. The results of these measurements led to an explanation of the reason for the calorimetry transitions. The investigation of the superstructure under uniaxial drawing revealed clearly the transition from a lamella structure to a fibrillae structure. Furthermore, the atomic structure and the superstructure as well as their orientation under uniaxial drawing were examined. Thereby, the change in crystallization became apparent and, in particular, a strain induced crystallization for the low crystalline samples could be observed.dc.description.abstract
Languagededc.language.iso
PublisherUniversität Ulmdc.publisher
LicenseStandard (Fassung vom 03.05.2003)dc.rights
Link to license texthttps://oparu.uni-ulm.de/xmlui/license_v1dc.rights.uri
KeywordAmorphous and semicrystalline PPdc.subject
KeywordCrystal structuredc.subject
KeywordElastic polypropylene (PP)dc.subject
KeywordMetallocen catalystsdc.subject
KeywordPhase transitionsdc.subject
KeywordSAXSdc.subject
KeywordStrain induced crystallizationdc.subject
KeywordWAXSdc.subject
KeywordX-rays. Scatteringdc.subject
TitleRöntgenstrukturuntersuchungen an metallocenkatalysierten Polypropylenendc.title
Resource typeDissertationdc.type
DOIhttp://dx.doi.org/10.18725/OPARU-98dc.identifier.doi
URNhttp://nbn-resolving.de/urn:nbn:de:bsz:289-vts-39826dc.identifier.urn
GNDKristallstrukturdc.subject.gnd
GNDPhasenübergängedc.subject.gnd
FacultyFakultät für Naturwissenschaftenuulm.affiliationGeneral
Date of activation2004-04-29T15:27:38Zuulm.freischaltungVTS
Peer reviewneinuulm.peerReview
Shelfmark print versionZ: J-H 10.382 ; W: W-H 7.754 ; ZAV: J-H 9.163 ; WAV: W-H 8.150uulm.shelfmark
DCMI TypeTextuulm.typeDCMI
VTS-ID3982uulm.vtsID
CategoryPublikationenuulm.category


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