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The use of in situ Fourier Transform Infrared (FTIR) to follow PU reaction kinetics has been studied using a heated probe matching the PU material temperature. The results obtained show that, although not giving access to concentration of formed chemical bonds, the technique is a unique tool to assess subtle differences in catalysts behavior during actual PU formation, going beyond the currently used but restrictive characterization of catalysts in terms of gelling, blowing or trimerization grades. Examples of the use of the technique for the development of new amine catalysts are given for flexible and rigid foams. For flexible foams, it is shown that FTIR characterizes the gel potency in good agreement with the behavior of known gel catalyst molecules and is therefore a good tool to develop new ones. Results comparing gel strength and foam emission data show that several experimental grades have potential to be brought on the JEFFCAT® Catalyst range. They also confirmed the good performance of commercial low emission grades such as JEFFCAT® ZF-10 as blow catalyst and JEFFCAT® ZR-50, DPA and Z-130 as gel catalysts. For rigid foams, it is shown that FTIR provides good insight into the extent of trimer formation and is therefore the technique of choice to optimize catalyst blends for best fire performance and processing.

The aim of this investigation is to ascertain whether the mode of action of melamine in exible polyurethane (PU) involves condensed phase chemistry in terms of promoting char formation. A combination of in situ 1 H NMR analysis, solid state 13 C NMR characterization of chars prepared ex situ, and normal TGA and DSC has been employed. Solid state 13 C NMR indicates that there is no major discernible difference in the structure of the dichloromethane-insoluble chars prepared with and without melamine, the remaining polyol only accounting for 20±25 % of the total carbon at 350°C, but still being quite mobile. However, in situ 1 H NMR provides de®nitive evidence that melamine acts in the condensed phase in terms of promoting the formation of rigid char which forms in more signi®cant quantity by 450°C. No increase in the residue yields is observed by TGA upon melamine addition, probably due to a combination of the small sample size and open sample holder in relation to the in situ 1 H NMR analysis which also involves fairly slow heating.

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