The effect of different ammonium structure of quaternary ammonium resin on the electrochemical properties

Abstract The quaternary ammonium resin is synthesized by the ring‐opening reaction of an epoxy resin with a tertiary amine in the presence of a proton donor in the solution. This kind of resin can be dispersed in the water phase to form a conductible milky dispersion. In this study, different kinds of tertiary amines including the full‐alkyl group and the ester group‐containing or urethane group containing tertiary amine are reacted with DGEBA‐type epoxy resin to synthesize the quaternary ammonium resins. The resin characteristics and the electrochemical properties of its emulsion are investigated. In addition, properties of the emulsion prepared from tertiary amine salt resin are also measured for comparison. It is found that if the substituted groups of the ammonium structure of the quaternary ammonium resin are all alkyl groups, rupture voltage of the emulsion is very low. But when one of the substituted group contains an ester group or an urethane group, rupture voltage increases remarkably and the resin can be used for electrodeposition. Meanwhile, the electrodeposition theory of quaternary ammonium resin and its thermal cross‐linking reaction and the electrochemical properties of coemulsion prepared by mixing the quaternary ammonium resin and the tertiary amine salt resin are also discussed. © 1993 John Wiley & Sons, Inc.