Miscibility and specific interactions in blends of poly(4-vinylphenol) andpoly(2-ethoxyethyl methacrylate)

The properties of the hydrogen-bonded polymer blends of poly(4-vinylphenol) and poly(2-ethoxyethyl methacrylate) are presented. Spectroscopic techniqu es such as C-13 solid-state NMR and FT-IR are used to probe specific intera ctions of the blends at various compositions. Spectral features from both t echniques revealed that site-specific interactions are present, consistent with a significant degree of mixing of the blend components. Changes in che mical shift and line shape of the phenolic carbon and carbonyl resonances i n the C-13 CPMAS spectra of the blends as a function of composition are int erpreted as resulting from changes in the relative intensities of two close ly overlapped signals. A quantitative measure of hydrogen-bonded carbonyl g roups using C-13 NMR has been obtained which agreed well with the results f rom FT-IR analyses. It is also shown that C-13 NMR can be used to measure t he fraction of hydroxyl groups associated with carbonyl groups, which was n ot possible previously using FT-IR due to extensive overlapping of bands in the hydroxyl stretching region. The results of measurements of H-1 T-1 and 1H T-1 rho indicate that PVPh and PEEMA are intimately mixed on a scale le ss than 2-3 nm.