Preparation of composite epoxy networks by eco-friendly epoxy curing agents

Abstract Epoxy-based materials, known for their exceptional durability, are extensively used across various fields. However, a significant drawback of epoxy resins is that their curing agents, typically derived from petroleum, can pose environment risks. This study aims to develop new systems as alternatives to petroleum-derived curing agents. The incorporation of environmentally friendly curing agents in epoxy resins has the potential to significantly reduce the carbon footprint and decrease health risks to living organisms. For this purpose, the amine modified three-dimensional zeolite imidazolate framework (ZIF) was first prepared. Subsequently curing studies were carried out using epoxy resins composed of a petroleum-derived resin, a plant-based resin, and their mixtures. The resulting ZIF and amine-functionalized ZIF were characterized using FTIR and XRD techniques. Epoxy films were then prepared with three different curing agents across three distinct epoxy resin systems. Mechanical, thermal, and chemical analyses of the films were performed. Additionally, coatings were applied to glass surfaces, and their surface properties were evaluated. In reactions involving ZIF for epoxidized resorcinol, it was observed that the curing temperature shifted slightly to a higher range from 95 to 131 °C. The thermal degradation temperatures of the films containing ZIF also increased, resulting in more thermally stable materials. The maximum weight loss temperatures increased by 168 °C for RDGE and by 88 °C for the mixture of RDGE and ESO. Improved thermal stability can lead to a longer service life and greater performance in extreme conditions. Graphical Abstract Explores sustainable alternatives to petroleum-based curing agents in epoxy resins. ZIF with amine groups as eco-friendly curing agents was synthesized and functionalized. Thermal stability in epoxy films using ZIF-based curing agents was enhanced. Mechanical, thermal, and surface properties of ZIF-incorporated epoxy coatings were evaluated