Universal Features of Manifestation of Relationship between Local and Segmental Dynamics of Glassy Polymers at Terahertz Frequencies in IR Spectra

Temperature dependences of low-frequency IR spectra of glassy polymers are studied in the range of ν = 0.24–4 THz (8–135 cm –1 ) at temperatures from 90 to 400 K. Analysis of these dependences revealed absorption corresponding both to individual and correlated torsional vibrations, which initiate th...

Full description

Saved in:
Bibliographic Details
Published in:Optics and spectroscopy 2022-12, Vol.130 (12), p.605-611
Main Author: Ryzhov, V. A.
Format: Article
Language:English
Subjects:
Anharmonicity
High temperature
Infrared spectroscopy
Lasers
Low temperature
Macromolecules
Optical Devices
Optics
Photonics
Physics
Physics and Astronomy
Polymers
Spectra
Terahertz frequencies
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Temperature dependences of low-frequency IR spectra of glassy polymers are studied in the range of ν = 0.24–4 THz (8–135 cm –1 ) at temperatures from 90 to 400 K. Analysis of these dependences revealed absorption corresponding both to individual and correlated torsional vibrations, which initiate the relaxation dynamics. The temperature evolution of the IR spectra in the range of terahertz frequencies exhibits three universal behaviors, namely, the low-temperature regime corresponding to the anharmonicity of torsional vibrational motions, the high-temperature regime caused by the contribution of α relaxation (glass formation), and the intermediate stage related to the activation of the conformational mobility of chains due to the β transition. The results obtained are applicable to polymers with both hydrogen and van der Waals bonds between macromolecules.
ISSN:0030-400X
1562-6911
DOI:10.1134/S0030400X22130045