Polymeric Emulsions of Polyethylene Glycol in Water Prepared by Flow-induced Phase Inversion Emulsification: The Effect of Polymer Molecular Weight

Abstract: Polyethylene glycol (PEG)/water emulsions were prepared by the flow-induced phase inversion technique using various molecular weights of PEG. The aim of this study is to investigate the effect of molecular weight on the emulsification process. A Brabender® mixer was used for dispersing the polymers in water. The stability, morphology and particle size distribution were determined for the prepared emulsions. It was found that stability increases with increasing the molecular weight of PEG, approaching 96% for PEG with a molecular weight of 600000. The polymer particle size was in the submicron scale (0.10–0.17 µm), also increasing with increased PEG molecular weight. The PEG-6000 emulsion showed a relatively small median particle size (d50 = 0.27 µm), corresponding to 50% of the particles smaller than 0.27 µm in diameter, while PEG-600000 resulted in d50 over 2.9 µm. There was a noticeable increase of water content for the emulsion of PEG with a molecular weight of 600000.