Polymeric surfactants based on polysiloxanes-graft-poly (oxyethylene) for stabilization of multiple emulsions

Polymers consisting of hydrophilic and hydrophobic segments have been suggested as emulsifiers for stabilization of multiple emulsions. Attempts have been made to produce and use new polymeric surfactants based on polysiloxane-graft-poly(oxyethylene) for stabilization of water-in-oil-in-water (W/O/W) multiple emulsions. Hydrophobic comb-grafted copolymers have been used at the inner interface to obtain stable small droplet size water-in-oil emulsions. Hydrophilic comb-grafted copolymers with similar structures but with high density grafting and long poly(oxyethylene) chains have been used to stabilize the outer interface of the W/O/W emulsion. Stable multiple emulsion formulations with very slow release rates can be obtained when using the two types of silicone emulsifier.