Artifact Correction in Temperature-Dependent Attenuated Total Reflection Infrared (ATR-IR) Spectra

Area of Science:

• Polymer Science
• Spectroscopy
• Materials Science

Background:

• Aliphatic polyesters, such as poly[(R)-3-hydroxybutyrate- co-(R)-3-hydroxyhexanoate] (PHBHx), are important biodegradable polymers.
• Temperature-dependent spectroscopic analysis is vital for understanding polymer behavior.
• Accurate spectral data processing is essential for reliable analysis.

Purpose of the Study:

• To develop and validate a spectral processing method for temperature-dependent attenuated total reflection infrared (ATR-IR) spectra.
• To analyze the spectra of a specific biodegradable polyester, PHBHx.
• To improve the reliability of data for subsequent analysis, such as two-dimensional correlation spectroscopy (2D-COS).

Main Methods:

• Development of a spectral processing workflow for ATR-IR spectra.
• Application of the method to temperature-dependent spectra of PHBHx.
• Implementation of corrections for diamond absorbance, baseline, ATR effects, and normalization.
• Utilizing two-dimensional correlation spectroscopy (2D-COS) for advanced analysis.

Main Results:

• Key processing steps include diamond absorbance correction, baseline correction, ATR correction, and normalization.
• The order of processing steps significantly impacts data reliability.
• Normalization methods require careful selection to prevent artifacts in crystalline-sensitive bands.
• The developed method yields more reliable spectral data for polymer analysis.

Conclusions:

• A robust spectral processing method was established for temperature-dependent ATR-IR analysis of aliphatic polyesters.
• The study highlights the critical importance of meticulous data correction and processing order.
• Caution is advised in selecting normalization techniques to ensure accurate interpretation of polymer structural changes.