SHEAR-RATE, CONCENTRATION, MOLECULAR-WEIGHT, AND TEMPERATURE VISCOSITY DEPENDENCES OF HYALURONATE, A WORMLIKE POLYELECTROLYTE

The shear flow of hyaluronate solutions are studied on well characterized samples from bacterial sources. The dependence of the zero-shear viscosity, eta0, with polymer concentration, molecular weight, and temperature are discussed. The behavior of this semirigid ionic polymer differs, in some way, from that of flexible polymers in solution. In particular, the slope of the plot of log eta0 vs log M at fixed polymer concentration, C, is equal to 4 instead of 3.4 in the more concentrated domain. Nevertheless the concentration dependences of eta0 have been analyzed on the basis of models developed for flexible polymers.and polyelectrolytes. These models seem to apply to wormlike polymers with a presence of a limited semidilute region. The onset of shear thinning is found to be well characterized from the inverse of the longest relaxation time (tau(r)-1) in the solution taking into account C, M, and T dependences. The differences with hyaluronates of animal sources are attributed to the protein content in these samples.