1979 年 28 巻 4 号 p. 276-284
The authors studied on the antifoaming properties of vicinal glycols which were different in chain length and the position of neighbouring hydroxyl groups. 1, 2-Hexane-, 2, 3-hexane-, 3, 4-hexane-, 1, 2-octane-, 2, 3-octane-, 3, 4-octane-, 4, 5-octane-, 1, 2-decane-, 2, 3-decane-, 3, 4-decane-, 4, 5-decane-, 5, 6-decane-, 1, 2-dodecane-, 2, 3-dodecane-, 3, 4-dodecane-, 4, 5-dodecane-, 5, 6-dodecane-, and 6, 7-dodecanediols were derived from the corresponding olefins, which were prepared by the Wittig reactions, by the hydroxylation with hydrogen peroxide or potassium permanganate, or by the Meerwein-Ponndorf reduction of acyloins. The antifoaming power of these glycols was evaluated by the Ross and Miles method for the aqueous solutions of sodium dodecylbenzenesulforate, benzylhexadecyldimethylammonium chloride or p-nonylphenyl poly(oxyethylene) ether (n=15) as foaming agents. The results were expressed as immediate reading of foam height and reading of foam height after 5 min as a function of concentration of diols. From the results summarized in Fig.-1Fig.-16, it is evident that 5, 6-dodecanediols are superior to octanol, a commercial antifoaming agent, and comparable to silicone antifoamers. The antifoaming power of the glycols is larger when the two hydroxyl groups are located near center of the alkyl chain, but the symmetrical glycols where two hydroxyl groups centered on the alkyl chain are not so good.