Application of Generalized Two-Dimensional Infrared Correlation Spectroscopy to the Study of a Hydrogen-Bonded Blend

Abstract

In the preceding studies in this series, generalized two-dimensional (2D) infrared correlation spectroscopy has been applied to the study of polymer blends with relatively weak intermolecular interactions. In this paper, a miscible system with strong intermolecular interactions, hydrogen-bonded blends of poly(4-vinyl phenol) (PVPh) and poly(methyl methacrylate) (PMMA), is considered. It has been found that band positions in 2D plots are dependent on the data sets used, due to large peak shifts and/or bandwidth changes. This observation complements our preceding studies, in which it was found that new features correspond to maxima, minima, or points of inflection in the difference spectra used to generate the 2D plots and are not normal modes of vibration of specific functional groups. Great care needs to be taken in order not to interpret artifacts of the procedure in terms of new spectroscopic features.