Colloid and Polymer Science

, Volume 278, Issue 11, pp 1103–1108 | Cite as

Preparation of waterborne dispersions of epoxy resin by the phase-inversion emulsification technique. 2. Theoretical consideration of the phase-inversion process

  • Z. Z. Yang
  • Y. Z. Xu
  • D. L. Zhao
  • M. Xu
SHORT COMMUNICATION

Abstract

 A theoretical consideration of the phase-inversion technique to prepare waterborne particles based on the experimental facts of the phase inversion process given in part 1 of this series is presented. The deformation and breakup of the water droplets dispersed in an epoxy resin phase under shear action are analyzed in terms of microrheology. The interaction and coalescence dynamics among the water droplets stabilized by an interfacial layer formed by the emulsifier molecules are discussed in terms of Derjaguin–Landau–Verwey–Overbeek theory and effective collision theory, respectively. A criterion for the completion of phase-inversion is that the attraction among the water droplets exceeds the entropic repulsion. Thus, a physical model of phase-inversion is proposed to predict the effects of some control variables on the phase-inversion process as well as the structural features of the waterborne particles, by which the experimental results could be well interpreted. It is indicated that the achievement of phase inversion is determined by the dynamic coalescence among the water droplets before the phase-inversion point (PIP). If the dynamic coalescence among the water droplets is ignored, phase inversion is achieved completely and sub- micron-sized particles are prepared. In comparison, if the dynamic coalescence is significant, phase inversion is achieved incompletely and a large complex water-in-oil-in-water structure is prepared. In the case of complete phase inversion, it is shown that the size of the waterborne particles is comparable with the size of the water droplets before the PIP.

Key words Bisphenol A epoxy resin Waterborne dispersions Phase-inversion emulsification Physical method Mechanism 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • Z. Z. Yang
    • 1
  • Y. Z. Xu
    • 1
  • D. L. Zhao
    • 1
  • M. Xu
    • 1
  1. 1.State Key Laboratory of Polymer Physics and Chemistry Center for Molecular Science Institute of Chemistry The Chinese Academy of Sciences Beijing 100080, China e-mail: yangz@pplas.icas.ac.cn Fax: +86-10-2559373CN

Personalised recommendations