Crosslinking kinetics of the formation of lignin‐aminated polyol‐based polyurethane foam

Abstract FTIR‐ATR (Fourier Transform Infrared‐Attenuated Total Reflectance) spectroscopic analysis was used to study the kinetics of the formation of the polyurethane foam, which was prepared by reacting a mixture of lignin‐aminated polyol (LAP) and glycol (PEG) with diphenylmethane diisocyanates (MDI‐50) in the presence of water as blowing agent. The crosslinking reactions were followed by monitoring the change of the absorbance of the NCO group at 2270 cm −1 in FTIR‐ATR spectra. The apparent activation energy ( E a ) calculated according to n‐ th order reaction model was 16.44 kJ/mol, and the frequency factor ( A ′) was 2.69 min −1 . Furthermore, the crosslinking reaction is approximated to be a first‐order reaction. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012