Infrared Spectroscopy in Analysis of Polymer Structure–Property Relationships
Polymers and Rubbers
Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Pennington, B. D. 2006. Infrared Spectroscopy in Analysis of Polymer Structure–Property Relationships. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2006
Infrared (IR) spectroscopy is the measurement of the intensity of IR radiation absorbed at specific wavelengths, which can be used for the characterization of solid, liquid, gas, fiber, and powder samples. This technique allows molecular level identification of surface, interfacial, and bulk regions owing to its high selectivity and sensitivity. Quantitative measurement of molecular functionalities is accomplished by comparison with standards of known concentrations. The IR spectroscopic methods covered in this article include transmission, internal reflectance, reflection–absorption, diffuse reflectance, photoacoustic (PA), and step-scan techniques. Common applications of IR spectroscopy include polymer blending, adhesion, surface analysis, kinetics, and multidimensional studies.
The molecular specific information IR spectroscopy provides is one of the most useful aspects of this technique when compared to other common analytical methods. Compared with gas chromatography/mass spectrometry (GC/MS) which reaches parts per billion detection limits, IR spectroscopy, which is much less sensitive, provides nondestructive analysis. The depth resolution of X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) is several orders of magnitude better than IR spectroscopy, yet the ultrahigh vacuum (UHV) operating conditions of these techniques would destroy volatile samples. While the lateral resolution of scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and transmission electron microscopy (TEM) techniques is superior to IR spectroscopy, these methods require tedious sample preparation. IR spectroscopy offers sensitivity to a wide range of samples with limited sample preparation needed.