The waterborne dispersions of epoxy resin were prepared by the phase inversion emulsification technique.Rheological behavior and its relationship with the structural change of the systems were studied. It was shown that theconcentrated dispersions were highly viscoelatic and pseudoplastic

which was attributed to the formation of a physicalnetwor among tbe waterborne particles via hydrogen bond. The dilutc dispersions were Newtonian fluids. The discrete clusters composed of small waterborne particles were found in diluted dispersions.With increasing solid content

there existed a structural transition via percolation through a cluster-cluster aggregation mode to form the physical network

which was qualitatively evidenced by the TEM morphologies.