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RAFT mediated polysaccharide copolymers
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_ | 1867613996010438656 |
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| access_status_str | Open Access |
| author | Fleet, Reda |
| author2 | Sanderson, R. D. |
| author_browse | Fleet, Reda Sanderson, R. D. |
| author_facet | Sanderson, R. D. Fleet, Reda |
| author_sort | Fleet, Reda |
| 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:10019.1/2526 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:45:00.328Z |
| 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:10019.1/2526 RAFT mediated polysaccharide copolymers Fleet, Reda Sanderson, R. D. McLeary, J. B. Grumel, V. University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. RAFT Polysaccharide Graft copolymers Xanthate Addition polymerization Dissertations -- Polymer science Theses -- Polymer science Chemistry and Polymer Science Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2006. Cellulose, one of the most abundant organic substances on earth, is a linear polymer of D-glucose units joined through 1,4-β-linkages. Cellulose is however not easily processed without chemical modification. A number of techniques exist for the modification of cellulose, of which the viscose process is one of the most widely applied. Grafting of synthetic polymeric chains onto or from cellulosic materials is an useful technique that can be used to combine the strengths of synthetic and natural polymers dramatically, so changing the properties of cellulosic materials (pulp, regenerated cellulose, cellulose derivatives). In this study five model xanthate (Reversible Addition-Fragmentation chain Transfer (RAFT)/Macromolecular Design through Interchange of Xanthates (MADIX)) agents, namely, monofunctional, difunctional, trifunctional and tetrafunctional species of the form S=C(O-Z)-S-R, with different leaving groups and different activating moieties, were prepared and then studied to determine the feasibility of cellulose modification via addition fragmentation processes. These agents were characterized by Nuclear Magnetic Resonance spectroscopy (NMR), Fourier Transform Infrared spectroscopy (FT-IR) and Ultraviolet spectroscopy (UV). Polyvinyl acetates (PVAc) in the form of linear, three armed and four armed star shaped polymers were then successfully synthesized in reactions mediated by these xanthate RAFT/MADIX agents Xanthates were applied to polysaccharide materials using the viscose process (xanthate esters were formed directly on a cellulosic substrate, with subsequent alkylation) Grafting reactions were then conducted with the polysaccharides; cellulose was modified with vinyl acetate, [this is an example of a surface modification of natural polymers that is of interest in various industries, such as textiles and paper manufacture]. Analysis of the graft copolymers was conducted via Size Exclusion Chromatography (SEC), Liquid Adsorption Chromatography (LAC), Thermogravimetric Analysis (TGA), and FT-IR. Polyvinyl acetate was successfully grafted onto three polysaccharides (cellulosic materials), namely Hydroxyl Propyl Cellulose (HPC), Methyl Cellulose (MC) and cellulose. The study showed that the modification of cellulosic substrates with defined grafts of vinyl acetate can be easily achieved through minor modifications to existing industrial techniques. 2008-07-09T09:33:39Z 2010-06-01T08:51:18Z 2008-07-09T09:33:39Z 2010-06-01T08:51:18Z 2006-12 Thesis http://hdl.handle.net/10019.1/2526 en University of Stellenbosch application/pdf Stellenbosch : University of Stellenbosch |
| spellingShingle | RAFT Polysaccharide Graft copolymers Xanthate Addition polymerization Dissertations -- Polymer science Theses -- Polymer science Chemistry and Polymer Science Fleet, Reda RAFT mediated polysaccharide copolymers |
| title | RAFT mediated polysaccharide copolymers |
| title_full | RAFT mediated polysaccharide copolymers |
| title_fullStr | RAFT mediated polysaccharide copolymers |
| title_full_unstemmed | RAFT mediated polysaccharide copolymers |
| title_short | RAFT mediated polysaccharide copolymers |
| title_sort | raft mediated polysaccharide copolymers |
| topic | RAFT Polysaccharide Graft copolymers Xanthate Addition polymerization Dissertations -- Polymer science Theses -- Polymer science Chemistry and Polymer Science |
| url | http://hdl.handle.net/10019.1/2526 |
| work_keys_str_mv | AT fleetreda raftmediatedpolysaccharidecopolymers |