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Low-Frequency Raman Spectroscopy on Amorphous Poly(Ether Ether Ketone) (PEEK)
Tomoko Numata1,2, Naomoto Ishikawa3, Toshihiro Shimada4
1Department of Systems Design Engineering, Akita University, 1-1 Tegatagakuen-machi, Akita 010-8502, Japan.
Materials (Basel, Switzerland)
|August 10, 2024
Summary
Low-frequency Raman spectra of amorphous poly(ether ether ketone) (PEEK) revealed distinct vibrational modes. The Ph-CO-Ph intermolecular vibrational mode, crucial for PEEK
Area of Science:
- Polymer Science
- Materials Science
- Spectroscopy
Background:
- Poly(ether ether ketone) (PEEK) is a high-performance thermoplastic known for its excellent mechanical and thermal properties.
- Raman spectroscopy is a powerful technique for probing molecular vibrations and structural characteristics of materials.
- Understanding the vibrational dynamics of amorphous PEEK is crucial for predicting its behavior and optimizing its applications.
Purpose of the Study:
- To investigate the low-frequency Raman spectra of amorphous poly(ether ether ketone) (PEEK).
- To identify and characterize specific vibrational modes present in amorphous PEEK.
- To correlate observed spectral features with the intermolecular order in PEEK.
Main Methods:
- Utilized Raman spectroscopy to analyze amorphous PEEK samples.
- Employed wide-angle X-ray diffraction (WAXS) to confirm the amorphous nature (zero crystallinity) of the PEEK sample.
- Compared spectral data of amorphous PEEK with previously studied crystalline samples.
Main Results:
- Observed the disappearance of a low-frequency peak at 135 cm⁻¹ in amorphous PEEK, which was present in crystalline samples.
- Identified a new peak at 50 cm⁻¹ in crystallized PEEK, which was absent in the amorphous state.
- Found that the intensity of the 50 cm⁻¹ peak increased with increasing crystallinity, suggesting its dependence on intermolecular order.
Conclusions:
- The study identified key low-frequency Raman spectral features unique to amorphous PEEK.
- The Ph-CO-Ph-type intermolecular vibrational modes were associated with the observed peaks at 135 cm⁻¹ and 50 cm⁻¹.
- Intermolecular order significantly influences the Ph-CO-Ph vibrational mode in the low-frequency region of PEEK.
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