Polymers from renewable sources: 5. Myrcene-based polyols as rubber-toughening agents in glassy polyurethanes
| Autor: | John L. Cawse, John L. Stanford, Richard H. Still |
|---|---|
| Rok vydání: | 1987 |
| Předmět: |
chemistry.chemical_classification
Materials science Polymers and Plastics Organic Chemistry Rubber toughening Izod impact strength test Epoxy Polymer chemistry.chemical_compound Polybutadiene chemistry Natural rubber visual_art Materials Chemistry visual_art.visual_art_medium Composite material Glass transition Polyurethane |
| Zdroj: | Polymer. 28:368-374 |
| ISSN: | 0032-3861 |
| DOI: | 10.1016/0032-3861(87)90187-x |
| Popis: | A reactive liquid rubber based on hydroxy-functionalized polymyrcene was used to modify a highly-crosslinked, glassy polyurethane network. During the polymerization, the products formed from the reacting liquid rubber and the polyurethane matrix components become incompatible leading to precipitation of the rubber as a discrete particulate phase. Phase-separation in the resultant rubber-modified polyurethanes is essentially complete, and the materials possess improved stress-strain and impact properties relative to the unmodified network, without reduction of the glass transition temperature (155°C) of the network. Impact data have been analysed using linear elastic fracture mechanics to give GIC, the critical strain-energy release rate. On incorporating low levels of polymyrcene liquid rubber ( w w ) in the polyurethane matrix, GIC increased and passed through a maximum value. The mechanisms of energy dissipation accounting for the toughness changes are reviewed and compared with those observed in epoxy resins modified by polybutadiene-based liquid rubbers. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|