Molecular dynamics in polyethylene and ethylene-1-butene copolymer investigated by NMR methods
| Autor: | S. Głowinkowski, Stefan Jurga, Sieghard E. Wanke, Monika Makrocka-Rydzyk |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
chemistry.chemical_classification
Materials science Polymers and Plastics Organic Chemistry Spin–lattice relaxation General Physics and Astronomy 1-Butene Polymer Polyethylene Carbon-13 NMR chemistry.chemical_compound Crystallinity chemistry Polymer chemistry Materials Chemistry Physical chemistry Orthorhombic crystal system Monoclinic crystal system |
| Zdroj: | European Polymer Journal. 38:961-969 |
| ISSN: | 0014-3057 |
| DOI: | 10.1016/s0014-3057(01)00272-5 |
| Popis: | H and 13 C NMR spectra and 1 H spin-lattice relaxation times T1 and T1q have been employed to study the structure and molecular dynamics in polyethylene and ethylene-1-butene copolymer in the temperature range from 100 to 370 K. Results are interpreted in terms of a, b and c -relaxation, as well as methyl group rotation. The activation energies for all motions were established. The incorporation of 1-butene into ethylene chain leads to an increase of mobility in amorphous and crystalline phases as well as appearance the 13 C resonance characteristic to the monoclinic structure in addition to the orthorhombic observed in both polymers. The crystallinity degree derived from T1q in studied polymers is close to that determined using DSC method. 2002 Elsevier Science Ltd. All rights reserved. |
| Databáze: | OpenAIRE |
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