PREPARATION OF WATER BASED DISPERSIONS OF EPOXY RESIN BY PHASE INVERSION EMULSIFICATION TECHNIQUE——STUDY ON RHEOLOGICAL BEHAVIOR OF PHASE INVERSION
YANG Zhenzhong, XU Yuanze, ZHAO Delu, XU Mao (Polymer physics Laboratory, Institute of Chemistry, Chinese Academy of Sciences, Beijing\ 100080)
The tests including steady stress sweep and dynamic frequency sweep were performed to characterize the rheological behavior of phase inversion evolution at high concentration of the emulsifier (e.g.10.9%). It is shown that the phase inversion is complete, which means that all water molecules in the system are transformed to be continuous phase at the phase inversion point. The viscosity of the system before the phase inversion point is almost constant independent on stress, which is the characteristics of Newtonian fluid. The systems after the phase inversion point exhibit high viscoelasticity and strong pseudoplasticity at relatively high stress. This is attributed to the formation of a new static structure among waterborne particles through hydrogen bond between the emulsifier and water molecules, and the static structure is broken at high stress.