Optimizing Polyurethane Catalyst PC-77 in Flexible Foam Sealing Materials for Automotive Gaskets Ⅰ. Introduction Polyurethane (PU) flexible foam is widely employed in the automotive industry, particularly in the production of gaskets and sealing materials. These materials provide crucial functions such as vibration damping, noise reduction, and environmental sealing, preventing the ingress of dust, water, and...