Vinyl-Substituted Silphenylene Siloxane Copolymers: Novel High-Temperature Elastomers
| Autor: | Simon W. Kantor, Ulrich Lauter, William J. MacKnight, Klaus Schmidt-Rohr |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
chemistry.chemical_classification
Materials science Polymers and Plastics Hydrosilylation Organic Chemistry Thermosetting polymer Polymer Elastomer Amorphous solid Inorganic Chemistry chemistry.chemical_compound chemistry Siloxane Polymer chemistry Materials Chemistry Thermal stability Glass transition |
| Zdroj: | Macromolecules. 32:3426-3431 |
| ISSN: | 1520-5835 0024-9297 |
| DOI: | 10.1021/ma981292f |
| Popis: | The synthesis of a series of vinyl-substituted silphenylene siloxane polymers of high molecular weight is described. 29Si NMR spectroscopy indicates that the polymers possess an exactly alternating microstructure of the silphenylene and siloxane moieties. The materials are completely amorphous with glass transition temperatures between −60 and −86 °C. All polymers degrade thermally only above 500 °C under both oxidative or inert atmosphere. The char yields at 900 °C increase with increasing vinyl content from 30% up to almost 70%. Cross-linking of a small fraction of vinyl groups by hydrosilylation gives materials with elastomeric properties. Dynamic mechanical experiments indicate that the bulk of vinyl groups cross-links thermally at temperatures above 230 °C. Therefore, the temperature window for possible applications of these materials as fire-safe elastomers extends from about −86 °C to approximately 230 °C. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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