O/W emulsions for cosmetics products stabilized by alkyl phosphates - rheology and storage tests

Alkyl phosphates are useful as cosmetic emulsifiers. Mono-/diphosphate mixt ures derived from long chain Guerbet alcohols combine good emulsification p roperties with easy handling. Model emulsions containing both emulsifier an d a polymeric thickener were characterized by rheological measurements, par ticle size distributions and stability tests. Emulsion stability was found to be related to the presence of a yield stress. The melting points and Krafft boundaries increase with chain length and can be greatly reduced by chain branching. Solid emulsifiers can form macrosco pically homogenous dispersions in water which thicken on heating above the Krafft boundary and re-cooling. These aqueous dispersions may also be used to stabilize emulsions and dispersions. (C) 1999 Elsevier Science B.V. All rights reserved.