Non-Aqueous Emulsions Stabilised by Nonionic Nonyl Phenol Ethoxylate Reactive Polymerisable Surfactants

A new series of nonionic polymerisable nonyl phenol ethoxylates (NPEs) has been prepared as organic solvent-soluble surfactants in which straight, branched and cyclic alkyls and phenyl acted as solvophilic segment and polyoxyethylene, or maleate chains as solvophobic segment. The new bifunctional reactive surfactants were prepared by reacting polyoxyethylene 4-nonyl -2-propylenephenol nonionic reactive surfactant with maleic anhydride followed by esterification with poly (ethylene) glycol. The chemical structure of the prepared surfactants was determined by C-13 and H-1 NMR analyses. Surface activities of these surfactants in organic solvents including formamide, toluene and aqueous water solvent were determined by surface tension measurement. The results showed that these polymerisable NPE surfactants can reduce the surface tension of both polar and non-polar organic solvents. Stable non-aqueous emulsions of formamide/toluene system was prepared and exhibited excellent stability against coalescence for more than 6 months when stabilised by the modified surfactants. The initial location of the newly prepared reactive surfactants plays a crucial role in determining the type, stability and catastrophic phase inversion point of the resulted oil-in-oil emulsions. Correlation between the stability and the preferred emulsion type with the surface properties of the newly prepared reactive surfactants was addressed.