Technical Abstract: When potato starch granules are dissolved in aqueous medium, the two major components, amylopectin and amylose, do not mix together and form two separate layers like oil and water. This property of starch solutions can be used to isolate each component for industrial use. Study of starch solutions that includes the construction of "phase diagram" allows us to replace old techniques that required long and tedious steps to obtain purified form of starch components. In this report, the "phase diagram" of potato starch is presented. When polymers are blended commercially, the processing conditions usually subject these materials to complicated flows. Polymers are returned to the quiescent state after processing has been completed. The application of simple shear offers the possibility of modeling the behavior under flow in a more controlled environment. Monitoring the relaxation of the blend after the cessation of shear allows one to obtain insight into the kinetic processes during the approach of the final equilibrium state. Since it is already known that the behavior of polymer blend under flow is similar to that of polymer blend solution, we employed potato starch solution as a model system and studied the behavior under flow and compared with that of synthetic polymer solutions.