Viscoelastic Properties of Polyelectrolyte Solutions. 2. Steady-State Compliance

Steady-state compliance J_e of polyelectrolyte solutions was measured in the presence and absence of added salt. In dilute regions, J_e depends on molecular weight M, polymer concentration C, and concentration of added salt C_s. The M and C dependences are much stronger than that of nonionic polymers as given by J_e ∝ M^-2C^-3C₅. In entangled regions, on the other hand, J_e depends on C only in the same manner as for that of nonionic polymer solutions, but the concentration dependence is weaker than that of nonionic polymers as given by J_e ∝ C^-1.3. Moreover, the polymer concentration dependence of the weight-average relaxation time τ_w defined as the product of zero-shear viscosity η⁰ and J_e is found to increase with increasing C_s in semidilute regions for η⁰ and entangled regions for J_e. These features of J_e and τ_w in entangled regions can be explained by the same model as for zero-shear viscosity in Part 1.