The Rheological Properties of Poly(vinyl alcohol) Gels from Rotational Viscometry

摘要

A laboratory experiment was developed to follow the gelation of a polyvinyl alcohol (PVA) solution upon addition of borax by using rotational viscometry. The rheological properties of the gel were examined, measuring the dependence of viscosity and shear stress on the shear rate. Time-dependent studies were also conducted in which the viscosity of the PVA gel was evaluated as a function of time for different shear rates. A range of qualitative tests were subsequently conducted to demonstrate the phenomena of die swelling, spinability and the Weissenberg effect. Overall, this laboratory experiment has been successfully conducted by over 200 students.