the catalytic role of 2-ethyl-4-methylimidazole in polyurethane foam formation abstract: 2-ethyl-4-methylimidazole (emi) is a tertiary amine catalyst widely employed in the production of polyurethane (pu) foams. this article provides a comprehensive review of emi’s role in catalyzing the complex chemical reactions involved in pu foam formation, including its influence on gelation, blowing, and overall foam...