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Self-healing coatings based on thiol-ene chemistry
Thesis (PhD (Chemistry and Polymer Science)--University of Stellenbosch, 2009.
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| Format: | Thesis |
| Language: | English |
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Stellenbosch : University of Stellenbosch
2009
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| _version_ | 1867613975506583552 |
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| access_status_str | Open Access |
| author | Van den Dungen, Eric T. A. |
| author2 | Klumperman, Bert |
| author_browse | Klumperman, Bert Van den Dungen, Eric T. A. |
| author_facet | Klumperman, Bert Van den Dungen, Eric T. A. |
| author_sort | Van den Dungen, Eric T. A. |
| collection | Thesis |
| dc_rights_str_mv | University of Stellenbosch |
| description | Thesis (PhD (Chemistry and Polymer Science)--University of Stellenbosch, 2009. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/1274 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:44:41.084Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2009 |
| publishDateRange | 2009 |
| publishDateSort | 2009 |
| 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:10019.1/1274 Self-healing coatings based on thiol-ene chemistry Van den Dungen, Eric T. A. Klumperman, Bert University of Stellenbosch. Faculty of Science. Dept. of Chemistry and Polymer Science. Self-healing Thiol-ene chemistry Urea-formaldehyde microcapsules Dissertations -- Polymer science Theses -- Polymer science Thiols Coatings Coating processes Polymerization Thesis (PhD (Chemistry and Polymer Science)--University of Stellenbosch, 2009. The work presented in this dissertation describes the development of self-healing coatings based on thiol-ene chemistry. The approach was to synthesize capsules with thiol and ene compounds separately encapsulated. These capsules were embedded in various coating formulations and upon the formation of a crack with a razor blade, these capsules ruptured. This caused the healing agent to flow into the crack via capillary action and the thiol-ene healing mechanism was initiated. This resulted in recovery of the damaged coating and provided continued protection to the substrate. Pentaerythritol tetrakis(3-mercaptopropionate) (TetraThiol), 1,6-hexanediol diacrylate (DiAcrylate) and 1,6-hexanediol di-(endo, exo-norborn-2-ene-5-carboxylate) (DiNorbornene) are the thiol and ene compounds used in this study. Kinetic experiments indicated that both TetraThiol-DiAcrylate and TetraThiol-DiNorbornene monomer pairs undergo rapid polymerization and form a network within minutes upon exposure to UV radiation and with the addition of a photoinitiator. The TetraThiol-DiNorbornene monomer pair also showed a high rate of polymerization without the addition of a photoinitiator and/or exposure to UV radiation. Styrene-maleic anhydride (SMA) copolymers and chain-extended block copolymers with styrene (P[(Sty-alt-MAh)-b-Sty]) were synthesized via Reversible Addition-Fragmentation chain Transfer (RAFT)- mediated polymerization. These copolymers were used as surfactant in miniemulsification for the synthesis of core-shell particles with TetraThiol as the core material. It appeared that P[(Sty-alt-MAh)-b-Sty] block copolymers, sterically stabilized via the addition of formaldehyde, provide optimal stability to the core-shell particles. DiNorbornene is encapsulated via miniemulsion homopolymerization of styrene and well-defined, stable nanocapsules were obtained. TetraThiol and DiAcrylate microcapsules were synthesized via in-situ polymerization of urea and formaldehyde. Microcapsules with a particle size of one to ten micrometers and with a very smooth surface were obtained. These microcapsules and nanocapsules were embedded in poly(methyl acrylate) (PMA), styrene-acrylate and pure acrylic films and the self-healing ability of these coatings, after introduction of a crack with a razor blade, was assessed. Doctoral 2009-02-12T15:18:58Z 2010-06-01T08:17:08Z 2009-02-12T15:18:58Z 2010-06-01T08:17:08Z 2009-03 Thesis http://hdl.handle.net/10019.1/1274 en University of Stellenbosch application/pdf Stellenbosch : University of Stellenbosch |
| spellingShingle | Self-healing Thiol-ene chemistry Urea-formaldehyde microcapsules Dissertations -- Polymer science Theses -- Polymer science Thiols Coatings Coating processes Polymerization Van den Dungen, Eric T. A. Self-healing coatings based on thiol-ene chemistry |
| title | Self-healing coatings based on thiol-ene chemistry |
| title_full | Self-healing coatings based on thiol-ene chemistry |
| title_fullStr | Self-healing coatings based on thiol-ene chemistry |
| title_full_unstemmed | Self-healing coatings based on thiol-ene chemistry |
| title_short | Self-healing coatings based on thiol-ene chemistry |
| title_sort | self healing coatings based on thiol ene chemistry |
| topic | Self-healing Thiol-ene chemistry Urea-formaldehyde microcapsules Dissertations -- Polymer science Theses -- Polymer science Thiols Coatings Coating processes Polymerization |
| url | http://hdl.handle.net/10019.1/1274 |
| work_keys_str_mv | AT vandendungenericta selfhealingcoatingsbasedonthiolenechemistry |