FT-IR Analysis of Polyurethane Foams with the Use of Mid-Infrared Fibers

Abstract

Infrared fibers have found tremendous applications in the study of many systems. In this paper, mid-IR/FT-IR spectrometry was used to study the reaction kinetics of polyurethane foams. Polyurethane foams were produced with two different silicone surfactants, BF-2370 and B-8404. Data were collected for two hours on an FTS-60A/896 Bio-Rad Spectrometer. The temperature was monitored during the foam production. Infrared spectra at every 50 temperature drop were curve-fitted by use of Galactic GRAMS/386™ software. Based on the curve-fit results, percentages of free, monodentate and bidentate urea, and free and hydrogen-bonded urethane formed during the foam formation were determined. Relative reaction rates for the formation of urea and urethane were also calculated. For the BF-2370 surfactant foam, the initial rate of urethane formation was much greater than the urea formation. The rate of urea formation increased with time and was greater than urethane formation when it reached a steady state. Different results were obtained with the B-8404 foam, where both rates were in a steady state during the polymer formation. These results gave a better understanding of structural changes that occur with temperature in the formation of polyurethane formations.