The curing process and the moisture transport in a tetrafunctional epoxy resin as investigated by FT-NIR spectroscopy

An epoxy resin formulation composed of tetraglycidyl-4, 4? diaminodiphenylmethane (TGDDM) and 4, 4? diaminodiphenylsulfone (DDS) was investigated by Fourier transform near-infrared (FT-NIR) spectroscopy. In situ isothermal measurements allowed us to obtain the concentration versus time curves of the various reactive groups present in the system, thus affording a complete characterization of the curing process. The same experimental approach was used to monitor the transport of moisture into the resin at several temperatures. The data gathered in this way revealed a good agreement with conventional gravimetric measurements, which verifies the reliability and accuracy of FT-NIR spectroscopy for the study of these transport processes.