Determining the Conformation and Dimensions of the PEG Macromolecule in Water-PEG-NaOH Systems via Vicosometry

The kinematic viscosity of water-polyethylene glycol (PEG)-NaOH systems is investigated at a temperature of 293.15 K, 0-0.05 mol % of NaOH, and concentrations of PEG in the range of 0-5 g/dL. Fractions of polyethylene glycol with different molecular masses are considered (1000, 1500, 3000, 4000, and 6000). Based on experimental data for the kinematic viscosity at this concentration of NaOH, calculations are performed for the characteristic viscosity of the given solutions, the Huggins constant, parameter α in the Kuhn-Mark-Houwink equation, the swelling coefficient of macromolecules of polyethylene glycol, the characteristic viscosity in a θ-solvent, the mean-square distance of a macromolecular chain of PEG in solution and a θ-solvent, and the length of a Kuhn segment in solution and in a θ-solvent. It is found that the macromolecular coil of polyethylene glycol is permeable to the surrounding liquid (water-NaOH). Upon an increase in the concentration of NaOH, the volume of the coil is reduced and the flexibility grows.