Hydrocarbon Mixtures with Alkyl Phosphoric Acid Derivatives

1 Hydrocarbon Mixtures with Alkyl Phosphoric Acid Derivatives 

we consider mixtures of hydrocarbon oils and hydrophobic particles. We also include consideration of precursors of such mixtures. This includes mixtures where the hydrocarbon is a wax, which must first melt before it disperses. It also includes mixtures where a precursor of the hydrophobic particle is present, such as a fatty acid, a water-soluble soap, or an alkyl phosphate acid ester, which under certain circumstances can react at the oil-water interface to form hydrophobic particles of calcium soap [27] or calciumalkyl phosphate. 

That mixtures of alkyl phosphoric acid esters and mineral oils produce synergistic antifoam effects when incorporated into detergent formulations was apparently first described by Hathaway and Heile [28]. Mixtures of mineral oil and stearyl acid phosphate were particularly effective. Carter [29] subsequently demonstrated that the effect required the presence of calcium in the aqueous phase. Conversion of the 

We have discussed the issue of deactivation by disproportionation of PDMS-hydrophobed silica antifoams during foam generation in some detail in Chapter 6, By contrast, there seems little evidence that mixtures of hydrocarbons and either calcium alkyl phosphates or alkyl phosphoric acid esters deactivate during washing 

FIGURE 8.7 Antifoam effectiveness F = (volume of air in foam with antifoam/volume of air in absence of antifoam) of calcium mono-stearyl phosphate-liquid paraffin mixtures as function of proportion of calcium mono-stearyl phosphate. Aqueous surfactant solution 0,5 kg m commercial sodium alkyl (Ciq i4) benzene sulfonate. Concentration antifoam 1,2 kg m . Foam generated by cylinder shaking at ambient temperature (22 2°C), (Reprinted from Colloids Surf. A, 85, Garrett, RR, Davis, J, Rendall, H.M., 159, Copyright 1994, with permission from Elsevier,) 

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