Determining Conformations and Sizes of Polyethylene Glycol Macromolecules in Water–Polyethylene Glycol–LiOH Systems by the Viscometry Method

The kinematical viscosity of water-polyethylene glycol-LiOH systems is studied at 293.15 K for the LiOH molar fraction of 0–0.05 and the PEG concentration of 0–5 g/length. Polyethylene glycol fractions of different molecular masses (1000, 1500, 3000, 4000, and 6000) are considered. Experimental data on the kinematic viscosity for a given LiOH concentration are used to calculate the following quantities: intrinsic viscosity of studied solutions, Huggins coefficient, parameter α in the Mark-Houwink equation, swelling coefficient of polyethylene glycol macromolecules, intrinsic viscosity in the θ solvent, mean square distance of the PEG macromolecular chain in the solution and in the θ solvent, length of the Kuhn segment in the solution and the θ solvent. It is shown that macromolecular polyethylene glycol coils are permeable for the surrounding liquid (water-LiOH) and that their volumes decrease and the macromolecule flexibility increases with increasing LiOH concentration.