RHEOLOGICAL BEHAVIOR OF SOME POLYMERIC SIZING AGENTS ALONE AND IN ADMIXTURES

Solutions of seven polymeric sizing agents, viz., four kinds of polyvi nyl alcohols (PVAs), carboxymethyl starch (CMS), and sodium polyacryla te (PA) in addition to their binary mixtures, at a concentration of 10 %--were theologically characterized at 80 degrees C. It was found that : (1) all these solutions behaved as non-Newtonian shear thining fluid s that displayed measurable thixotropic character, and (2) the apparen t viscosity, at a constant shear rate, and the extent of thixotropy de pended both on the kind of-sizing agent and on the composition of the binary mixtures. The flow behavior index and the shear thining index o f each solution, as deduced from the power law, were estimated, and he nce the degree of pseudoplasticity and the flow properties of each sol ution were evaluated.