Miscibility and interactions in blends of two proton-donating polymers: Poly(acrylic acid)/poly(p-vinylphenol) blends

Abstract

Blends of poly(acrylic acid) (PAA) and poly(p-vinylphenol) (PVPh) were prepared from N,N-dimethylformamide (DMF) and ethanol solutions. The DMF-cast blends exhibited single Tg'S, as shown by modulated differential scanning calorimetry, whereas the ethanol-cast blends had double Tg'S. Fourier transform infrared spectroscopy showed that there was a specific interaction between PAA and PVPh in the DMF-cast blends. The single-Tg blends cast from DMF showed single-exponential decay behavior for the proton spin-lattice relaxation in both the laboratory frame and the rotating frame, indicating that the two polymers mixed intimately on a scale of 2-3 nm. © 2003 Wiley Periodicals, Inc.