2-Ethyl-4-Methylimidazole (EMI-24)

2-Ethyl-4-Methylimidazole (EMI-24, also known as 2E4MI) is a liquid or low-melting-point imidazole accelerator for epoxy resin systems, offering higher ambient-temperature reactivity than 2-MI while maintaining good latency at room temperature. EMI-24's melting point of approximately 40–45°C means it is liquid at typical warm processing temperatures (40–60°C) and provides meaningful acceleration in epoxy systems at temperatures above 80°C. It is more soluble in liquid epoxy resins at room temperature than 2-MI, resulting in faster cure at lower temperatures (80–120°C), making it preferred for applications requiring moderate cure temperatures without full-temperature post-cure. EMI-24 is a widely used accelerator for DICY-based one-component epoxy adhesives, powder coatings, composites, and filament winding systems where cure at 80–120°C is practical. Dosage is typically 0.3–2 phr on epoxy resin, providing room-temperature shelf life of 2–6 months and cure in 30–60 minutes at 120°C. EMI-24 is also used as a standalone catalyst for epoxy homopolymerization at elevated temperature. It is available as a neat liquid (above 45°C), as solution in epoxy resin, or as microencapsulated grades for enhanced latency.