Water diffusion into epoxy resin: a 2D correlation ATR-FTIR investigation

The water diffusion process in a novolac epoxy resin (EP) was studied by 2D ATR-FTIR spectroscopy, the originally broad water OH bands in 1D-IR spectra can be effectively differentiated into three bands, located at 3610, 3460 and 3240 cm−1, respectively. The bands at 3460 cm−1 (antisymmetric) and 3240 cm−1 (symmetric) are assigned to the OH stretching vibration of water fully hydrogen-bonded with other water molecules, while the 3610 cm−1 band could be attributed to the stretching vibration of water partially hydrogen-bonded with epoxy resin. The mechanism of the water diffusion process in EP is also discussed.