The Influence of Polyurethane Trimerization Catalysts on Friability and Compression Properties of Polyisocyanurate (PIR) Foam Abstract: Polyisocyanurate (PIR) foams, prized for their superior fire resistance and thermal insulation, are increasingly employed in construction and industrial applications. However, the inherent brittleness and potential for friability of PIR foams can limit their durability and long-term performance. This...