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Updated: Feb 4, 2026
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Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
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Microstructure of amide-functionalized polyethylenes determined by NMR relaxometry
Shira Haber1, Nicodemo R Ciccia2,3, Zhengxing Peng1,4
1Materials Sciences Division, Lawrence Berkeley National Laboratory 1 Cyclotron Road Berkeley CA 94720 USA shira.haber@biu.ac.il reimer@berkeley.edu.
Chemical Science
|February 2, 2026
Summary
Amide functional groups in polyethylene were studied using nuclear magnetic resonance (NMR) techniques. These amidyl groups were found to localize in the rigid amorphous fraction, influencing material microstructure and properties.
Area of Science:
- Polymer Science
- Materials Science
- Organic Chemistry
Background:
- Amidation of polyethylenes introduces amide groups, enhancing material properties.
- The impact of these functional groups on polymer microstructure remains largely unknown.
Purpose of the Study:
- To investigate the microstructural changes in amide-modified polyethylenes.
- To determine the location and influence of amidyl groups within the polymer matrix.
Main Methods:
- Solid-state nuclear magnetic resonance (NMR) spectroscopy was employed.
- NMR relaxation techniques were used to measure chain mobility in different polymer regions.
- Analysis focused on crystalline, amorphous, and interphasial regions.
Main Results:
- A decrease in overall crystallinity was observed with increased amidation.
- Grafted amidyl groups were found to partition into the rigid amorphous fraction (RAF).
- NMR provided precise assessments of functional group location within the polymer microstructure.
Conclusions:
- Amidation alters polyethylene microstructure by concentrating functional groups in the RAF.
- Understanding functional group localization is key to tailoring properties of functional polyolefins.
- This study provides foundational insights into the structure-property relationships of amide-modified polyethylenes.
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