Self-emulsified waterborne epoxy hardener without acid neutralizers and its emulsifying and curing properties

Purpose The purpose of this study is to prepare a new self-emulsified waterborne epoxy hardener which can emulsify the liquid epoxy resin in aqueous media without addition of acid neutralizers. Design/methodology/approach Two synthetic steps were adopted to prepare novel self-emulsified amine-epoxy adduct type hardener composition based on the reaction of a commercially available polyetheramine, bisphenol A epoxy resin and triethylene tetramine. The different factors affecting the synthesis of the waterborne epoxy hardener were explored by emulsifying and curing properties. The process and products were analyzed and confirmed by FIRT. Findings Compared to an introduction of polyether as a hydrophilic segment in previous literature, whose reaction required Lewis acid catalysts and strict control of the presence of water, the introduction of polyetheramine to obtain a novel self-emulsified waterborne epoxy hardener were concise and convenient by mere two amine-epoxy addition steps in this research. Moreover, the final product offered good film formation with a practical value of mechanical properties, glass transition temperature and water-resistant property. Practical implications The self-emulsified waterborne epoxy hardener can be used to prepare water-resistant waterborne coatings from liquid epoxy resins while also providing the option of zero VOC formulations. Originality/value Introduction of hydrophilic polyether amine to prepare self-emulsified waterborne epoxy hardener without acid neutralizers has not been systematically studied previously.