Viscoelasticity of biodegradable polymer blends of poly(3-hydroxybutyrate) and poly(ethylene oxide)

The viscoelastic properties, measured via both steady shear and oscillatory experiments, for blends of biodegradable poly(3-hydroxybutyrate) (PHB) and poly(ethylene oxide) (PEO) were examined. We observed that PHB/PEO blends are miscible. The first normal stress difference, the shear stress, and the shear viscosity (obtained from the steady shear experiment) were correlated with the storage modulus, the loss modulus, and the complex viscosity (obtained from the oscillatory experiment) via either the Cox and Merz rule or other empirical equations. For biodegradable PHB/PEO blend systems, we found that both the viscous and the elastic behavior from the steady shear experiment are qualitatively related to those from the oscillatory experiment. (C) 2001 Published by Elsevier Science Ltd.