An interpenetrated system based on a tetrafunctional epoxy resin and a thermosetting bismaleimide: Structure-properties correlation

The kinetics and mechanism of the curing process of a thermosetting blend formed by tetraglycidyl‐4,4′‐diaminodiphenyl methane and N,N′‐bismaleimido‐4,4′‐diphenyl methane (BMI) cured in the presence of 4,4′‐diaminodiphenyl sulfone, was investigated in detail by Fourier transform infrared spectroscopy. Information on the molecular structure of the network formed upon curing was derived. Dynamic‐mechanical measurements on dry samples indicated an interpenetrated polymer network‐like structure. Sorption measurements at 70°C showed a reduction of the water uptake at equilibrium in the presence of substantial amounts of BMI in the system (43.5% body weight). Finally, the dynamic‐mechanical analysis of wet samples demonstrated a reduction of the plasticizing efficiency of the absorbed water in the presence of BMI. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1029–1042, 1998