Miscibility and rheology behaviors of poly(3‐hydroxybutyrate)/poly(p‐vinylphenol) blends with homogeneous amorphous compositions

The miscibility and rheology behaviors of poly(3‐hydroxybutyrate) (PHB) and Poly(p‐vinylphenol) (PVPh) blends were studied in this work. It was evidenced that the miscible amorphous system of the PHB/PVPh blends was formed when the PHB content was less than 40%(wt). Linear dynamic viscoelasticity of the blends in the amorphous condition was studied through oscillatory shear measurements. Time‐temperature superposition principle (TTS) was applicable in the experimental window. The Han plots (log G′ versus log G″) were temperature independent, but the curvatures in the terminal region were much less than 2 and became smaller with increasing of the PVPh. It was considered that this phenomenon might come from the presence of the change of the whole hydrogen bonding (self‐associated and the hydrogen bonding between hydroxyl group and ester group) in the blends. The Fourier transform infrared spectroscopy analysis supported this conclusion. It was found that the rubber plateau modulus for this blend system did not follow Wu's and Tsenoglou's model. This result was also caused by the presence of the hydrogen bonding. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.