The effect of molecular composition on the properties of linear low density polyethylene

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dc.contributor.advisorVan Reenen, A. J.
dc.contributor.authorKeulder, L.en_ZA
dc.contributor.otherUniversity of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science.
dc.date.accessioned2008-06-17T12:55:23Zen_ZA
dc.date.accessioned2010-06-01T09:01:50Z
dc.date.available2008-06-17T12:55:23Zen_ZA
dc.date.available2010-06-01T09:01:50Z
dc.date.issued2008-03en_ZA
dc.descriptionThesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2008.
dc.description.abstractIn this study linear low density polyethylene (LLDPE), a copolymer consisting of ethylene and 1-butene, was fractionated by the use of temperature rising elution fractionation (TREF). These fractions were then analyzed by crystallisation analysis fractionation, 13C NMR, high temperature size exclusion chromatography and DSC. The molecular distribution of the polymer was investigated. It was found that the polymer had a very broad distribution in its chemical composition. From these results it was also clear that the catalysts used for the polymerisation consist out of different active sites, producing chains with different molecular architecture. Subsequently the polymer was fractionated again by TREF and certain fractions were removed and the remaining material recombined. The removed fractions and recombined material were analyzed by 13C NMR, high temperature size exclusion chromatography, DSC and DMA. The results were compared with the bulk material and from this we could conclude the influence of the fractions removed on the material properties. This gave us more information on the influence of the chemical structure of the polymer on its mechanical properties. It was clear that by removing certain fractions with a certain chemical composition, the properties of the polymer are significantly influenced.en_ZA
dc.identifier.urihttp://hdl.handle.net/10019.1/2929
dc.language.isoen_ZAen_ZA
dc.publisherStellenbosch : University of Stellenbosch
dc.rights.holderUniversity of Stellenbosch
dc.subjectLinear low density polyethyleneen_ZA
dc.subjectMechanical propertiesen_ZA
dc.subjectTemperature rising elution fractionation (TREF)en_ZA
dc.subjectMolecular structureen_ZA
dc.subjectDissertations -- Chemistryen_ZA
dc.subjectTheses -- Chemistryen_ZA
dc.subject.otherChemistry and Polymer Scienceen_ZA
dc.titleThe effect of molecular composition on the properties of linear low density polyethyleneen_ZA
dc.typeThesisen_ZA
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