Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2006. / Synthesis of a series of poly (methylmethacrylate)-graft-poly (styrene) polymer was
carried out via free radical polymerization of methylmethacrylate and polystyrene
macromonomers. The macromonomers were synthesized via living anionic
polymerization techniques. Two series of macromonomers where synthesized with
different polymerizable end group functionalities, by termination with p-vinyl benzyl
chloride and 3-(dimethyl chloro silyl) propyl methacrylate. The branch density was varied
by controlling the composition feed ratio of the macromonomers to comonomer. Liquid
chromatographic techniques were used to fully characterize the chemical composition
and branch distributions of the graft polymer. Liquid chromatography under critical
conditions of adsorption of styrene coupling with Fourier Transform Infrared Spectra was
used to investigate the chemical composition and distribution of the branches in the
graft. Physical properties of the graft copolymers such as Tg and free volume were
determined using differential scanning calorimetry and positron lifetime spectrometry
respectively. The relationship between the chemical composition and the graft
copolymer properties such as Tg and free volume were investigated. The results show
that for long chain macromonomers phase segregation occurs in the graft copolymers. In
the case of shorter chain macromonomers at low content no phase segregation is
observed and the macromonomers have an antiplasticization effect on the graft
polymers.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/1758 |
| Date | 12 1900 |
| Creators | Elhrari, Wael |
| Contributors | Mallon, P. E., University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. |
| Publisher | Stellenbosch : University of Stellenbosch |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | 1266269 bytes, application/pdf |
| Rights | University of Stellenbosch |
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