Rheology of Miscible Polymer Blends with Hydrogen Bonding

Abstract

Linear dynamic viscoelasticity of miscible polymer blends with hydrogen bonding has been investigated. The polymer blend systems investigated are (1) blends of poly(vinylphenol) (PVPh) and poly(vinyl acetate) (PVAc), (2) blends of PVPh and poly(vinyl methyl ether) (PVME), (3) blends of PVPh and poly(2-vinylpyridine) (P2VP), and (4) blends of PVPh and poly(4-vinylpyridine) (P4VP). Fourier transform infrared (FTIR) spectroscopy was employed to find that both the intraassociation (self-association) of the phenolic −OH groups in PVPh and interassociation (intermolecular interactions) between the constituent components in each blend system have profound influence on the frequency dependence of dynamic moduli in the terminal region of the PVPh-based miscible blend systems. It has been found further that time−temperature superposition (TTS) is applicable to all four PVPh-based miscible blend systems forming hydrogen bonds, including the PVPh/PVME blends having the difference in component glass transition temperature (ΔTg) as large as 199 °C. This observation is quite different from the experimental observations in the literature, reporting that TTS failed for miscible polymer blends without specific interaction when ΔTg was greater than about 25 °C and the presence of concentration fluctuations and dynamic heterogeneity caused the failure of TTS. The experimental observations made from the present study suggest that the presence of concentration fluctuations and dynamic heterogeneity in the PVPh-based miscible blends forming hydrogen bonds (intermolecular interactions) between the constituent components might be very small, if not negligible.