Effect of sodium hydroxide on the interactions of polyethylene glycol macromolecules with water molecules

The rheological properties of dilute water solutions of polyethylene glycols with different molecular mass (1000, 3000, 6000, 8000, 20,000) were investigated in the temperature range 293-323°K in the presence of sodium hydroxide (0.1 mol/l). The intrinsic viscosities, Huggins constants, mean-square distance between the ends of the macromolecular chain, crossover concentrations and activation energies of viscous flow have been determined vs. temperature and molecular mass of polymers. It has been established that the macromolecular coils in the presence of sodium hydroxide (0.1 mol/l) in aqueous solutions of polyethylene glycols accept the unperturbed state as in theta solutions and the intrinsic viscosity becomes very sensitive to the molecular mass of polymers. The new approach for estimating the interaction energy per volume fraction between the macromolecule and solvent molecule has been proposed.