One-Step Synthesis of W/O and O/W Emulsifiers in the Presence of Surface Active Agents

The main goal of this study was to describe the method of the synthesis of the dodecyl-, tetradecyl-, hexadecyl- and octadecyl-propylene glycol emulsifiers in the presence of selected anionic and nonionic surfactants. Acyl propylene glycol emulsifiers were produced by esterification of propane–1,2-diol (propylene glycol, PG) with C(12:0)–C(18:0) fatty acids in the presence of anionic sodium dodecyl sulfate (SDS) and nonionic-poly(ethylene glycol) monolaurate (PEGML). The presence of SDS and PEGML in the reaction system caused microemulsion formation. Depending on the structure and amount of the surfactant in the system reactions proceeded at different rates and with different efficiency levels. The esterification of propylene glycol carried out under applied conditions causes products with the desired contents of propylene glycol monoesters (MAPG) to be obtained in a one-step reaction. Knowledge of the reaction kinetics creates the possibility to program the composition and properties of the synthesized emulsifiers. The interaction of nonionic, lipophilic MAPG with anionic, hydrophilic SDS or nonionic, hydrophilic PEGML influences the hydrophile–lipophile balance (HLB) values of the products which may be used to stabilize water-in-oil (W/O) and oil-in-water (O/W) emulsions. Use of the synthesized compounds allows stable emulsions to be prepared which include the following vegetable fats in the oil phase: mango oil, palm oil, shorea butter and hydrogenated soybean oil.