PROPERTIES OF HYDROXYPROPYLMETHYL CELLULOSE STABILIZED EMULSION IN THE PRESENCE OF SODIUM DODECYLSULFATE

Many food, pharmaceutical, cosmetic and chemical products exist in the form of emulsions. A common problem with emulsions is their instability. One method of effec-tive protection against coalescence of the particles is to raise the viscosity and lower surface tension by adding a polymer and low-molar-mass surfactant. Interaction be-tween polymer and surfactant could change the adsorption layer around the oil droplets in emulsion which effects emulsion stability. In this paper, the influence of low-molar-mass anionic surfactant, sodium dodecylsulfate (SDS), on the properties of hydroxypro-pylmethyl cellulose (HPMC) stabilized emulsion, has been investigated. Changes of viscosity and rheological properties of emulsion caused by the HPMC-SDS interaction in continuous phase were measured and stability of emulsions was observed during two months of storage. Significant increase in viscosity and stability of the emulsions was found at SDS concentrations leading to HPMC-SDS interaction in the continuous phase. Stability of emulsions changed with time and was influenced by the HPMC-SDS interac-tion