Dependence of the stability of a soap stock emulsion on the combined effect of sodium chloride and nonionogenic surfactant additives

Qualitative and quantitative compositions of soap stock were estimated by analytical methods and gas-liquid chromatography. The fat component of soap stock was isolated by conversion of the oil-in-water emulsion of the waste into that of the water-in-oil type under a combined effect of an electrolyte (sodium chloride) and a nonionogenic surfactant, oxyethylated nonylphenol (OP-7). A conclusion was made, on the basis of values obtained for the compression coefficient beta and surface pressure pi, that the emulsion system is hydrophobized and the linoleic acid monolayer contracts upon addition of sodium chloride and OP-7.