Modification of aqueous acrylic–polyurethane via epoxy resin postcrosslinking

Abstract An epoxy resin (E‐51)‐modified acrylic–polyurethane emulsion with triethylenetetramine (TETA) serving as the postcrosslinking agent was synthesized. The curing reaction between E‐51 and the curing agent TETA during the film‐forming course was monitored and identified by an infrared spectrophotometer. The stabilities of the single‐pack emulsion during the polymerization course as well as the storage stage were investigated. The effect of the epoxy resin was studied in terms of the dispersion size of the emulsion, the mechanical properties, as well as the swell in water and toluene of the cast film, The emulsion was shown to be stable when the epoxy content was below 20% based on the mass of the polyacrylate in the system. The tensile strength and the modulus and the water and toluene resistance were enhanced with increase of the epoxy resin. In contrast, the elongation at break was decreased. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 470–475, 2003