| Abstract: | The curing kinetics of two thermosetting systems based on a tetrafunctional epoxy resin was investigated by Fourier transform infrared spectroscopy. Two formulations were studied, in which the hardener was an aromatic diamine and a carboxylic dianhydride, respectively. The quantitative evaluation of the epoxy conversion was based on spectra collected in the near‐infrared range (8000–4000 cm−1) as well as in the medium infrared range (4000–400 cm−1). The kinetic parameters evaluated in the above frequency intervals were significantly different. The reasons for such a discrepancy are discussed critically. Several kinetic models, based on the widely employed Kamal approach, were applied to verify their predictive capability. Satisfactory results were obtained for the amine‐cured system, particularly with a modified equation taking into account the autocatalytic nature of the process as well as a limiting diffusional effect. Less accurate results were achieved for the anhydride‐cured system. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 532–540, 1999 |
