Viscoelastic properties of entangled polyelectrolyte solutions in the absence of added salt were measured over a wide range of polymer concentration, C, from the terminal to plateau regions. master curves of storage, G′, and loss, G″, moduli from the terminal to plateau regions are obtained irrespective of polymer concentrations, by using Gx, defined as the modulus at which G′ and G″ coincide with each other, asa characteristic modulus to superinpose the data. The master curves are similar to those of non-ionic polymer solutions, implying that the distribution of relaxation times of entangled polyelectrolyte solutions are not so much different from that of entangled non-ionic polymer solutions. Specific viscosity at zero shear-rate, ηspO, steady-state compliance, JeO, and Gx of entangled polyelectrolyte solutions can be understood by classifying the solutions into two regions, i.e. semidilute and concentrated regions. In the semidilute regions the polymer concentration dependence is given by and JeO ∞ Gx- ∞ C-.3 in salt-free solutions. In concentrated regions (C > 0.3 g/cm3), on the other hand, the polymer concentration dependence of ηsp0, Je0 and Gx becomes stronger than that in the semidilute regions. The steep increase of ηsp0 may be due to the significant increase of concentration dependence of local frictional coefficients, and the concentration dependence of Je0 and Gx may be understood by the uniform network model, like entangled non-ionic polymer solutions at high concentrations.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Materials Chemistry