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Synthesis and characterisation of hybrid graft copolymers of polydimethylsiloxane and polymethylmethacrylate
Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2007.
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| Format: | Thesis |
| Language: | en_ZA |
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Stellenbosch : University of Stellenbosch
2008
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| _version_ | 1867614021823234048 |
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| access_status_str | Open Access |
| author | Krugel, Gretha |
| author2 | Mallon, P. E. |
| author_browse | Krugel, Gretha Mallon, P. E. |
| author_facet | Mallon, P. E. Krugel, Gretha |
| author_sort | Krugel, Gretha |
| collection | Thesis |
| dc_rights_str_mv | University of Stellenbosch |
| description | Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2007. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/2224 |
| institution | Stellenbosch University (South Africa) |
| language | en_ZA |
| last_indexed | 2026-06-10T12:45:24.995Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2008 |
| publishDateRange | 2008 |
| publishDateSort | 2008 |
| publisher | Stellenbosch : University of Stellenbosch |
| publisherStr | Stellenbosch : University of Stellenbosch |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/2224 Synthesis and characterisation of hybrid graft copolymers of polydimethylsiloxane and polymethylmethacrylate Krugel, Gretha Mallon, P. E. University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. Synthesis of graft copolymers Polymers analysis Dissertations -- Chemistry Theses -- Chemistry Chemistry and Polymer Science Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2007. Hybrid graft copolymers of polydimethylsiloxane (PDMS) and polymethylmethacrylate (PMMA) were synthesised. PDMS macromonomers were synthesised anionically from the cyclic D3 monomer. This living polymerisation was terminated with a [3- (methacryloxy)propyl]-dimethylchlorosilane terminating agent which resulted in the functionalised macromonomer. These PDMS macromonomers and MMA monomer were copolymerised to form PMMA-g-PDMS hybrid copolymers by conventional free radical reactions. Synthesised and commercial methacryloxy-functionalised PDMS macromonomers having a range of molar masses were copolymerised with MMA to form graft copolymers of various chemical compositions. PDMS content in the graft copolymers could be varied by the amount of PDMS incorporated into the copolymer as well as by varying the length of the PDMS side chains. Size exclusion chromatography (SEC) results confirmed low PDI’s for the PDMS macromonomers synthesised anionically. NMR studies allowed characterisation of the synthesised PDMS macromonomers and PMMA-g-PDMS copolymers. It also allowed the determination of relative ratios of PMMA:PDMS in the graft copolymers. Gradient elution chromatography (GEC) was used successfully to monitor the presence and removal of the PDMS macromonomer from the graft copolymer products. The influence of PDMS content of the graft copolymers on retention time was also evaluated using this technique. Two dimensional chromatography confirmed the formation of PMMA-g-PDMS copolymer as well as PMMA homopolymer during some of the grafting reactions. GEC in the first dimension was coupled to SEC in the second dimension. PAS-FTIR studies allowed chemical characterisation of the graft copolymer and confirmed surface segregation of the PDMS. Atomic force microscopy (AFM) was also used to study the surface segregation of PDMS and looked at the relationship between surface polarity and increasing PDMS content. The study showed the effect of thermal treatment on the surface morphology of the hybrid polymers. Corona treatment was used to modify the surface structure of the graft copolymer films. Contact angle studies provided evidence of hydrophobic loss and recovery after corona for the hybrid polymer materials containing PDMS. This is one of the first reported examples of hydrophobicity recovery in these types of hybrid materials after corona treatment. Slow positron beam studies highlighted the formation of a thin silica like layer on the surface of the films after corona similar to that observed for pure cross-linked PDMS compounds. The positron studies enabled estimation of the thickness of the silica like layer. 2008-04-08T07:21:05Z 2010-06-01T08:43:44Z 2008-04-08T07:21:05Z 2010-06-01T08:43:44Z 2007-12 Thesis http://hdl.handle.net/10019.1/2224 en_ZA University of Stellenbosch 2229888 bytes application/pdf application/pdf Stellenbosch : University of Stellenbosch |
| spellingShingle | Synthesis of graft copolymers Polymers analysis Dissertations -- Chemistry Theses -- Chemistry Chemistry and Polymer Science Krugel, Gretha Synthesis and characterisation of hybrid graft copolymers of polydimethylsiloxane and polymethylmethacrylate |
| title | Synthesis and characterisation of hybrid graft copolymers of polydimethylsiloxane and polymethylmethacrylate |
| title_full | Synthesis and characterisation of hybrid graft copolymers of polydimethylsiloxane and polymethylmethacrylate |
| title_fullStr | Synthesis and characterisation of hybrid graft copolymers of polydimethylsiloxane and polymethylmethacrylate |
| title_full_unstemmed | Synthesis and characterisation of hybrid graft copolymers of polydimethylsiloxane and polymethylmethacrylate |
| title_short | Synthesis and characterisation of hybrid graft copolymers of polydimethylsiloxane and polymethylmethacrylate |
| title_sort | synthesis and characterisation of hybrid graft copolymers of polydimethylsiloxane and polymethylmethacrylate |
| topic | Synthesis of graft copolymers Polymers analysis Dissertations -- Chemistry Theses -- Chemistry Chemistry and Polymer Science |
| url | http://hdl.handle.net/10019.1/2224 |
| work_keys_str_mv | AT krugelgretha synthesisandcharacterisationofhybridgraftcopolymersofpolydimethylsiloxaneandpolymethylmethacrylate |