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Synthesis and characterization of graft and block copolymers using hydroboration
Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2006.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : University of Stellenbosch
2008
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| _version_ | 1867614101543321600 |
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| access_status_str | Open Access |
| author | Baleg, Abd-Almonam |
| author2 | Mallon, P. E. |
| author_browse | Baleg, Abd-Almonam Mallon, P. E. |
| author_facet | Mallon, P. E. Baleg, Abd-Almonam |
| author_sort | Baleg, Abd-Almonam |
| collection | Thesis |
| dc_rights_str_mv | University of Stellenbosch |
| description | Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2006. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/2931 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:46:41.344Z |
| 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:10019.1/2931 Synthesis and characterization of graft and block copolymers using hydroboration Baleg, Abd-Almonam Mallon, P. E. University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. Graft copolymers Block copolymers Hydroboration Dissertations -- Polymer science Theses -- Polymer science Chemistry and Polymer Science Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2006. Graft and block copolymers were synthesized using multifunctional and monofunctional macroinitiators to produce the copolymers. The process involved hydroboration of commercially available unsaturated rubbers and chain-end unsaturated macromonomers with 9-borabicyclo [3.3.1] nonane (9-BBN). The resulting secondary alkyl 9-BBN moieties in the starting materials were subsequently exposed to oxygen in the presence of free radical polymerizable monomers to facilitate the formation of graft and block copolymers. This research was initiated by first studying the hydroboration of a model compound, 2-hexene, in order to determine the optimal conditions for the graft reactions. The model compound was subsequently used as a macroinitiator to initiate the polymerization of methylmethacrylate (MMA). The same borane chemistry was extended to the synthesis of polystyrene (PS) block copolymers. Chain-end unsaturated PS macromonomers, synthesized by anionic polymerization, were effectively hydroborated and then polymerized to produce PS-b-PMMA block copolymers. The synthesis of polyolefin graft copolymers was subsequently achieved by hydroboration. Several commercial rubbers with different levels of unsaturated segments were efficiently grafted with vinyl monomers MMA and styrene (St) following the “graft from” approach. The grafted reactions were carried out under various reaction conditions to determine the effect of the following factors: concentration of oxygen, amount of borane and monomer concentration. By controlling these factors, different graft densities were achieved with high graft efficiencies. All reactions produced mixed products including unreacted (non-functional) macroinitiator, homopolymer, graft copolymer and in case of the highly unsaturated polymer a crosslinked gel. Finally, the chemical compositions as well as the molar mass distribution of the graft copolymers were fully characterized by different chromatographic techniques. 1H-NMR and FTIR were also used to confirm the structure of these copolymers. Gradient HPLC was developed and extensively used to characterize the graft copolymers. 2008-01-22T10:06:31Z 2010-06-01T09:01:52Z 2008-01-22T10:06:31Z 2010-06-01T09:01:52Z 2006-12 Thesis http://hdl.handle.net/10019.1/2931 en University of Stellenbosch 1411953 bytes application/pdf application/pdf Stellenbosch : University of Stellenbosch |
| spellingShingle | Graft copolymers Block copolymers Hydroboration Dissertations -- Polymer science Theses -- Polymer science Chemistry and Polymer Science Baleg, Abd-Almonam Synthesis and characterization of graft and block copolymers using hydroboration |
| title | Synthesis and characterization of graft and block copolymers using hydroboration |
| title_full | Synthesis and characterization of graft and block copolymers using hydroboration |
| title_fullStr | Synthesis and characterization of graft and block copolymers using hydroboration |
| title_full_unstemmed | Synthesis and characterization of graft and block copolymers using hydroboration |
| title_short | Synthesis and characterization of graft and block copolymers using hydroboration |
| title_sort | synthesis and characterization of graft and block copolymers using hydroboration |
| topic | Graft copolymers Block copolymers Hydroboration Dissertations -- Polymer science Theses -- Polymer science Chemistry and Polymer Science |
| url | http://hdl.handle.net/10019.1/2931 |
| work_keys_str_mv | AT balegabdalmonam synthesisandcharacterizationofgraftandblockcopolymersusinghydroboration |