The use of alternative blowing agents for the production of polyisocyanurate (PIR) rigid foam has created a need to better understand how various catalysts participate in isocyanurate formation. The improvement of isocyanate conversion to isocyanurate is one approach to overcome the greater flammability inherent with the use of hydrocarbons. In situ Fourier Transform Infrared (FTIR) has been used to follow the reaction kinetics of PIR development during foam preparation. The activity of amine catalysts for isocyanate conversion is characterized through the use of in situ FTIR. Identification of the reaction products formed from the blowing, gelling, and trimerization reactions provides the opportunity to profile the catalytic effects as the reaction proceeds. Several traditional amine catalysts used by PIR foam manufacturers have been evaluated. The design of catalyst blends in PIR formulation can now be based upon the results of the catalytic activity characterization. In this article, the focus is on understanding the synergies between catalysts used in PIR formulations. Real-time in situ FTIR is the technique of choice for the evaluation of catalysts blends for optimal performance and processing properties.

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