High-Temperature Pulsed-Field-Gradient Multidimensional NMR of Polymers
| Autor: | Weixia Liu, Toby Zens, Dale G. Ray, Peter L. Rinaldi |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
chemistry.chemical_classification
Nuclear and High Energy Physics Magnetic Resonance Spectroscopy Materials science Biophysics Analytical chemistry Polymer Nuclear magnetic resonance spectroscopy Polyethylene Condensed Matter Physics Biochemistry Spectral line chemistry.chemical_compound chemistry Copolymer Pulsed field gradient Two-dimensional nuclear magnetic resonance spectroscopy Coherence (physics) |
| Zdroj: | Journal of Magnetic Resonance. 140:482-486 |
| ISSN: | 1090-7807 |
| DOI: | 10.1006/jmre.1999.1868 |
| Popis: | The application of pulsed-field-gradient (PFG) techniques has been particularly important in providing the ability to detect 2D and 3D NMR cross peaks from minor structural components in synthetic organic polymers. The lack of mobility in a large percentage of polymers leads to rapid T2 relaxation which prevents the use of pulse sequences, such as the HMBC experiment, that operate based on coherence transfer via small, long-range J couplings. High-temperature NMR increases molecular motion with corresponding line narrowing (e.g., polyethylenes are typically analyzed at 120 degrees C). However, until now, the requirement for high temperature has precluded the use of PFG methods. Here we present data from a new probe which is capable of performing high-temperature PFG coherence selection experiments at temperatures typical of those used in many polymer analyses. We illustrate the performance of this probe with PFG-HMBC spectra of a copolymer from ethylene/1-hexene/1-butene at 120 degrees C. |
| Databáze: | OpenAIRE |
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