Two-dimensional Fourier-transform-Raman and near-infrared correlation spectroscopy studies of poly(methyl methacrylate) blends: 2. Partially miscible blends of poly(methyl methacrylate) and poly(4-vinylphenol)

Abstract Fourier-transform (FT)-Raman and near-infrared (NIR) spectra have been measured for poly(methyl methacrylate) (PMMA) and its partially miscible blends with poly(4-vinylphenol) (PVPh) of small content from 1 to 10 wt.%. Generalized two-dimensional (2D) correlation spectroscopy has been applied to analyze the composition-dependent FT-Raman and NIR spectral variations of the blends. The 2D FT-Raman correlation analysis is effective in analyzing the hydrogen-bonding interaction between PMMA and PVPh, which is responsible for the partial miscibility of the blends. It detects a band at 1706 cm −1 for the hydrogen-bonded CO of PMMA, and two bands at 599 and 549 cm −1 for the ester group whose Raman intensities are very sensitive to the intermolecular hydrogen bonding effect. The Raman-NIR hetero-correlation analysis detects two bands at 6764 and 4637 cm −1 for the hydrogen-bonded hydroxyl group of PVPh, and one band at 5052 cm −1 for the hydrogen-bonded carbonyl group of PMMA. All these bands are not readily identifiable from the one-dimensional (1D) spectra.