Two-Dimensional Correlation Study of Uniaxially Drawn Poly(Ethylene Terephthalate) Films by Using Attenuated Total Reflection Based Dynamic Compression Modulation Step-Scan Fourier Transform Infrared in Combination with Spectral Simulation Analysis by Density Functional Theory

Abstract

Attenuated total reflection (ATR) based dynamic compression modulation two-dimensional (2D) correlation studies of uniaxially drawn poly(ethylene terephthalate) (PET) films have been performed in combination with spectral simulation analysis by density functional theory (DFT). The dynamic 2D infrared (IR) correlation spectra in the region of the CCO stretching mode vibrations show four distinct correlation peaks located around 1290, 1265, 1248, and 1234 cm(-1). These bands can be clearly assigned to the combination bands or coupling modes of the CH in-plane bend of the benzene ring or the CH(2) deformation of the ethylene glycol unit, as well as CCO stretching vibrations, which are gauche conformer's characteristic bands, by DFT analysis. The sequential analysis of 2D correlation data shows that, upon applying the dynamic compression, the response of the side chain regions (ester groups) occurs first, followed by that of the backbone regions (benzene rings). The ATR based dynamic compression modulation 2D correlation spectroscopy in combination with DFT analysis can be a powerful tool for various polymer characterizations.

Dynamic behavior of polymer films in the presence of plasticizers by using ATR-based dynamic compression modulation step-scan Fourier transform infrared spectroscopy, and 2D correlation analysis

“…In combination with the previous sequential analysis results of C O and C-C-O vibrational bands regions, over all sequence of events can be determined as follows: In the PES without TPP, the sequential result is in good agreement with our previous paper [1][2][3], i.e., the dynamic response of the side-chain (C O) group is faster than that of the backbone (C-C-O stretching). However, with 15% TPP, this situation is altered; i.e., the response of the backbone (C-C-O stretching) bands occur faster than the side-chain (C O stretching) bands.…”

“…The Nexus 870's Synchronous Double Modulation (SDM) mode was used for all measurements [14]. Other experimental conditions and data manipulations for dynamic compression spectra were described in detail previously [1][2][3][4].…”

“…In our previous paper, we have demonstrated the utility of the attenuated total reflection (ATR)-based dynamic compression modulation spectroscopy by using several neat polymers, such as polyethylene terephthalate, and polyimide [1][2][3][4]. In most commercial applications, however, the use of a neat polymer alone is rather rare.…”

“…Dynamic infrared linear dichroism (DIRLD) spectroscopy has been proved to be a useful tool for this purpose [7][8][9][10][11]. The combination of ATR and dynamic compression technique we have developed [1][2][3][4], was found to provide useful information about molecular responses, even with very strong infrared absorption molecular groups, such as C O, COO, which often suffer from spectral saturation in conventional transmission DIRLD mode.…”

Polymer chain organization in tensile-stretched poly(ethylene oxide)-based polymer electrolytes

“…Furthermore, poly(ε-caprolactone) orients prior to poly(3-hydroxybutyrate) during stretching and plays in important role in the mechanism of polymer chain alignment in this system. Nishikawa et al [24] applied 2D correlation spectroscopy to elucidate the molecular changes associated with dynamic compression of uniaxially stretched poly(ethylene terephthalate). The analysis revealed that changes in the ester functional groups of the side chains occur before changes in the benzene rings composing the polymer backbone.…”