INVERSE EMULSIONS STABILIZED BY MONOETHANOLAMIDES OF FATTY ACIDS OF SUNFLOWER OIL

Abstract

The purpose of the study was to develop methods used to synthesise monoethanolamides of fatty acids of sunfl ower oil, to analyse the obtained surfactants, to obtain reverse emulsions based on diesel fuel and sunfl ower oil and to study their stability. The monoethanolamides of fatty acids of sunfl ower oil were obtained. The method for production is characterized by the application of sodium aminoethylate as a catalyst and the separation of the target product by means of centrifugation. Three fractions are formed by centrifugation: water, white solids, and a yellow liquid phase. According to HPGS-MS data, the white phase contains the monoethanolamides of all fatty acids, while the yellow phase does not contain the monoethanolamides of saturated fatty acids. The fraction containing the monoethanolamides of unsaturated fatty acids was used as an emulsifi er. Diesel fuel, sunfl ower oil, and water were used to obtain emulsions. The type of emulsion depends on the method of production. Ultrasonic irradiation is used to obtain direct emulsion, while mechanical agitation leads to the formation of the reverse emulsion. In each case, the type of emulsion was determined by the methods of dilution, the measurement of electrical conductivity, and optical microscopy. The nature of the emulsion destruction depends on the properties of the non-polar phase. The destruction of the diesel fuel based-inverse emulsion includes two stages. The fi rst stage involves the separation of a small volume of non-polar phase. The separation time depends on the volume of the hydrocarbon phase and the concentration of the emulsifi er. The second stage lasts a few weeks and involves the destruction of all the emulsion. The system of sunfl ower oil-water formation is characterised by the formation of the aqueous phase and the emulsion immediately after mixing. The volume of the emulsion directly depends on the volume of hydrocarbon phase. The emulsion is destroyed within three days. The greatest stability is observed with 3% (wt.) emulsifi er. Thus, the fraction of monoethanolamides of unsaturated fatty acids of sunfl ower oil was obtained and it was used together with diesel fuel and sunfl ower oil to produce inverse emulsions. The study revealed the dependence of the emulsion type on the production method, the nature of the inverse emulsion destruction, the dependence of their stability on the volume of the hydrocarbon phase and the concentration of the emulsifi er.

Keywords

• monoethanolamides
• fatty acids
• sunfl ower oil
• inverse emulsions
• emulsifi ers.