Molecular mobility in epoxidized butadiene/styrene triblock copolymer
| Autor: | Danuta Żuchowska, Przemyslaw Hruszka, Jan Jurga, Indu Malhotra |
|---|---|
| Rok vydání: | 1989 |
| Předmět: |
Materials science
Polymers and Plastics Organic Chemistry Spin–lattice relaxation Activation energy Epoxy Styrene chemistry.chemical_compound Polybutadiene Solid-state nuclear magnetic resonance chemistry visual_art Polymer chemistry Materials Chemistry Copolymer visual_art.visual_art_medium Glass transition |
| Zdroj: | Polymer. 30:467-470 |
| ISSN: | 0032-3861 |
| Popis: | Solid state nuclear magnetic resonance was carried out by the continuous wave and pulse methods for butadiene/styrene (B/S) triblock copolymers containing various amounts of epoxy groups. The effects of epoxidation on the second-order phase transition and molecular motion were examined. It was found that, with an increase in epoxy unit content from 0 to 0.31 groups 100 g copolymer, the glass transition temperature, T g , in polybutadiene matrix increased from 201 to 264 K. The main minimum of the spin-lattice relaxation time was also shifted to higher temperatures. The activation energy determined from the slope of the low temperature curve T 1 = f( 1 T ) was found to be 1.7 times higher in epoxidized copolymer containing 0.25 mol epoxy groups 100 g than in pure B/S copolymer. |
| Databáze: | OpenAIRE |
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