Rheological Properties of High Molecular Weight Poly(vinyl alcohol)/Dimethyl Sulfoxide/Water Concentrated Solutions

To establish basic data for the gel spinning of high molecular weigh (HMW) poly(vinyl alcohol) (PVA), the rheological properties of solutions of HMW PVA with a number-average degree of polymerization of 4,000 in dimethyl sulfoxide (DMSO)/water mixture were investigated in terms of three different polymer concentrations, 10 g/dl, 12 g/dl, and 14 g/dl, and various solution temperatures. Polymer concentration and solution temperature played a significant role in the rheological behaviour of HMW PVA solutions. Over the frequency range of 10 ^-1 to 10 ³ rad/s examined, PVA solutions showed shear thinning behaviour at lower temperatures. Furthermore, as the polymer concentration was increased, the extent of shear thinning also increased. In the plot of storage modulus of PVA solution with loss modulus, the slope was less than 2, indicating that the phase of PVA solutions in DMSO/water is heterogeneous.