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Mixtures of polyxypropylene polyols with water are typical systems with a lower critical miscibility temperature whose position is proportional to the concentration of end hydroxyl groups independently of the degree of branching of the polyethers. Replacement of low-molecular products with water. The polydispersity of the specimens of the polyoxypropylene polyols has a substantial effect on the phase diagrams, whose shapes are principally determined by the presence of the high-molecular fractions.

The results of the fractionation and the mol.wt. of polyoxypropylene polyols (POPP) produced by the polyaddition reaction of propylene oxide with potassium glycerate in glycerol have shown that the neutral polyether contains two diol types one of which is the product of water and propylene oxide, the other from hydrolysis of the cis -propylene groups in the mono-ol. The amount of the second diol type produced is equivalent to the cis -propylene groups content of the alkaline poly-ether. The OH-groups content of the neutral poly-ether equals the sum of the OH-groups present in the glycerol, water, allyl alcohol and from the cis -propenyl groups present in the alkaline polymer. This has qualitatively confirmed the mechanism of the chain transfer on the monomer during the anionic polymerization of the propylene oxide and has shown this reaction to be the only source of new OH-groups production during the polymerization.

A study was made of the molecular heterogeneity of polyethers, propylene oxide-ethylene oxide copolymers. Thin layer chromatography using silica gel was applied. Separation is based on the difference in adsorption interaction of hydroxyethyl and hydroxypropyl units in the molecule. Four solvent systems were selected to separate both homopolymers of propylene oxide and copolymers with broad distribution according to composition. It was found possible to use thin layer chromatography to determine the composition and structure of copolymers.

The temperature dependence of the viscosity of linear polypropylene glycols (PPG) of various mol.wt. was studied in the range from −50 to +50°C, amongst them that of a sample in which the hydroxyl end groups had been substituted by methyl groups. The temperature-viscosity functions of all the samples were found to be described by the Williams-Landell-Ferri empirical formula. The type of dependence in this formula of the parameters on the mol.wt. and the hydroxyl group content of the PPG was well explained by the theories dealing with the relaxation processes as a consideration of the free volume.