Mechanical properties of polyacrylic acid in aqueous solution

The pH and temperature dependence of the rigidity and the dynamic viscosity was observed for polyacrylic acid in aqueous solution. For sodium polyacrylate in aqueous solution, the effects of the concentration of the solution and of the amounts of added monovalent and divalent cations on the mechanical properties were measured at various temperatures. The rigidity for these solutions shows a maximum value at a certain pH or at particular temperature. The observed behavior may be explained by the proton or charge fluctuations between identical ionizable carboxyl groups.