Pentamethyl Diethylenetriamine (PC-5) Catalyzed Reactions in Flame-Retardant Foams Abstract: Pentamethyl diethylenetriamine (PC-5) is a tertiary amine catalyst widely employed in the production of polyurethane (PU) foams, particularly those requiring enhanced flame retardancy. This article provides a comprehensive overview of PC-5’s role in the formation and flame-retardant behavior of PU foams. We discuss its chemical properties,...