Abstract
Non-Newtonian flow of concentrated dioxane solutions of five polyvinyl chlorides(PVC) of different molecular weights has been studied. The dependences of the apparent and zero-shear viscosities on the rate of shear, molecular weight, and concentration are very similar to that in PVC-cyclohexanone solution.
The log-log plots of zero-shear viscosity against concentration for PVC-dioxane solutions are represented by two straight lines intersecting at one point (critical concentration, Cc). The slopes of lines are 5. 4 above Cc and 2.9 below Cc, respectively.
Furthermore, the products of critical concentration in volume fraction of polymer, VZC, multiplied by the chain length Z are found in the rannge from 130 to 210. The value Ccρ√Z densit of solution) is approximately constant and independent of the chain length as same as in the previous study on PVC-cyclohexanone solution. These results do not follow the Bueche′s theory.
Ccρ√Z value in dioxane is explained reasonably by using an Equivalent Gel Sphere Model, if the PVCchain association in dioxane solution is considered.
