Eco-friendly and cost-effective epoxy binder for polymer mortar utilizing oregano oil-based hardener

Polymer mortar, consisting of a polymer binder and aggregates, offers superior properties such as enhanced strength, durability, and corrosion resistance compared to the traditional cement-based mortars. Within the polymer-based mortar, epoxy resin is one of the most commonly used resins owing to its high performance. However, its widespread adoption is hindered by costs and environmental concerns, particularly the dependence of bisphenol A-containing epoxide, a substance harmful to human health. In this work, a novel epoxy hardener derived from oregano oil (OEO) was developed to create a more eco-friendly and cost-effective binder for polymer mortar. The inclusion of OEO-based hardeners reduced the viscosity of the binder and accelerated the curing process. The Mannich base structure of the hardener induced more reactive sites in the epoxy system, resulting in a denser crosslinked network. Polymer mortars fabricated with this novel hardener exhibited improved mechanical properties, bonding strength, and corrosion resistance compared to conventional epoxy mortars. Scanning electron microscopy images also revealed a stronger interfacial bond between the epoxy resin and the aggregates. This study demonstrates the potential of OEO-based hardeners to enhance the performance of epoxy binders, providing a sustainable alternative for polymer-based mortar applications.