Abstract: The effects of partially hydrolyzed polyacrylamide(HPAM), xanthan gum(XC)and lignosulfonate(LS)on the middle phase microemulsion containing petroleum sulfonate, mixed n-butyl and i-propyl alcohols and mineralized water have been studied by phase volume, interfacial tension(IFT), viscosity and solubilizing parameter measurements. Introducing polymers into the microemulsion caused slight increase of IFT, and no obvious change was observed in viscosity of middle phase. The volume of the middle phase microemulsion was decreased as the concentration of HPAM increased. Increase of LS led to disapearing of middle phase, forming Winsor 2 microemulsion system.

Key words: middle phase microemulsion, physical property, hydrolyzed polyacrylamide, xanthan gum, lignosulfonate