Shear Rate Dependence of Orientation Angle and Shape of Dispersed Droplets in Immiscible Polymer Blends under Steady Shear Flow
Yoshiaki TAKAHASHI, Takeshi MURAYAMA, Naotomo IMURA and Ichiro NODA
Abstract:Structural changes of dispersed domains in immiscible polymer blends under steady shear flow are directly observed by using cone-plate and coaxial cylinder geometries to analyze the orientation angle and the detailed shape of the domains. It was observed that the orientation angle have rather broad distributions even at the high shear rate. The ellipsoidal domains are not ellipsoid of revolution. At a certain steady state, domains having larger volume than the average volume are more elongated in the flow direction than the smaller ones. Shear stress and first normal stress difference cannot be calculated from average shape of observed domains. Key Words:Immiscible polymer blend, Ellipsoidal domain, Orientation angle, Steady shear flow