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 alpha in the Mark-Houwink equation, swelling coefficient of polyethylene glycol macromolecules, intrinsic viscosity in the theta solvent, mean square distance of the PEG macromolecular chain in the solution and in the theta solvent, length of the Kuhn segment in the solution and the theta 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.