FTIR studies on 2K polyurethane paint

Abstract

Two-component (2K) solvent-borne polyurethane paint, commonly used as automobile coatings and in recent years, increasingly being used as exterior aerospace topcoats, was studied for its characteristic polymerization and its reaction kinetics when factors such as temperature, stiochiometic / volume ratio and baking time were varied. The production of urethane and urea bonds (-C=O and a??NH), and the reduction of isocyanate (NCO) bond were studied to track the reaction kinetics. In situ transmission Fourier Transform Infrared (FTIR) spectroscopy was used and it proved to be a better technique than the conventional ones as there was totally no physical contact with the paint surface and hence no modification to the reaction and the surface topography.