1965 年 14 巻 5 号 p. 247-249
Polypropyleneglycols of the lower molecular weights are easily soluble in water, but they become progressively less soluble with increase in the propyleneoxide units. The molecular weights of the polypropyleneglycols showing any remarkable solubility in water are limited up to about 2000 and the polypropyleneglycols of these molecular weight ranges show very high surface activities. They were tested by measurement of surface tension, wetting, and dye-dispersing power, etc., and it was shown that polypropyleneglycols of molecular weight of about 2000 have the most high surface activity and strong dye-dispersing effect. It is noted that polypropyleneglycols entirely consisting of the repeated propyleneoxide structural units show the surface activity, while molecules of most typical surface active agents generally known have the typical hydrophobic and hydrophilic parts.