Studies on Metal-Containing Surfactants. II.

Surface Active Properties of Binary Aqueous Solutions of Dodecyl Pyridinium Chloride-Metal (Groups I a and II a) Soap (Part 2)

Abstract

Wetting power and foaming characteristics of binary aqueous solutions of dodecyl pyridinium chloride (DPC) -metal soap were investigated. Metal soaps used were laurates, stearates, oleates and ricinoleates of alkaline and alkaline earth metals. Molar ratios of DPC : metal soap in binary solutions were 2.5250 : 1.
When metal soap was added to DPC, remarkable synergistic effects were found in wetting power for discs of felt or cotton cloth. Alkaline earth metal salts were superior than alkaline metal salts in producing the effects. Particularly, barium ricinoleate is excellent in this respect.
Foaming power and foam stability of the most binary solutions markedly increased as compared with that of the each component. Among the kinds of metal salts constituting binary systems, barium salts of long chain fatty acids showed better values. All the laurates studied were excellent. Lithium stearate was excellent while magnesium stearate had no effects, inversely it showed very low foaming property. Then alkaline earth metal salts are not always superior than alkaline metal salts.
In respect of synergistic effect, there are considerable similarities between the results of wetting power, foaming characteristics and that of surface tension, contact angle.