Emulsions of polyethylhydridesiloxane in water for electrophoretic coatings

Abstract

An investigation on formation of polyethylhydridesiloxane-in-water emulsions was made. It was shown that an effective method of making emulsions is an ultrasonic dispersion. Optimum conditions of stable emulsions preparation were determined in the presence or absence of emulsifiers. For the preparation of stable and electrically charged emulsions for electrophoretic coatings the effect of a variety of the ionogenic surfactants on electric properties of the dispersions of polyethylhydridesiloxane has been investigated. In the absence of emulsifiers the electrokinetic potential of the emulsion particles ( ζ) is equal to +4 mV. Introduction of sodium alkylsulfate into the system results in the formation of stable negatively charged emulsions with high ζ potentials. Emulsions possessing positive charge were formed using cationic surfactants of the quaternary ammonium compounds type. The prepared emulsions are sufficiently stable and do not segregate when standing for 2 or more months. It was established that high aggregative stability of such dispersed systems is caused by the electrostatic factor effect.