Preparation of Epoxy Resin Emulsifiers with Different Structures and a Comparative Study of their Properties

Abstract The structure of epoxy resin emulsifier has important influence on the stability of epoxy resin emulsion/dispersion. However, there is no systematic comparative study so far about the effect of the structure of the epoxy resin emulsifier on their physiochemical properties and performance. In this work, two types of linear (AB and ABA types) and one type of branched epoxy resin emulsifiers were prepared by using bisphenol A epoxy resin E‐44 as the hydrophobic chain segment A and polyethylene glycol (PEG) as the hydrophilic chain segment B, and their physicochemical properties were compared. It has been found that the branched epoxy resin emulsifier is more hydrophilic than the two kinds of linear epoxy resin emulsifiers as a result of higher content of hydrophilic PEG chains. More importantly, the solubilization ability of the branched epoxy resin emulsifier to toluene is much higher than that of the two linear epoxy resin emulsifiers and exhibits an unique behavior, i. e., it increases monotonically with increasing hydrophilic PEG chain length. This work shed a light on the structural importance of epoxy resin emulsifier on its physicochemical properties and may provide a better choice of emulsifiers for the preparation of stable epoxy resin emulsions/dispersions.