FTIR isothermal cure kinetics and morphology of dicyanate ester resin/polysulfone blends

The isothermal cure of a dicyanate ester monomer by in situ Fourier transform infrared spectroscopy (FTIR) has been investigated. The degree of cyanate conversion and the kinetic parameters have been determined for cobalt catalyzed and uncatalyzed resin as well as for polysulfone (PSF) modified systems at different curing temperatures. The cyanate conversion increases with the increment of temperature and with the addition of a catalyst, but it does not vary with the addition of PSF. In all the systems studied, the rate of reaction showed a second-order dependence on the cyanate concentration in the kinetically controlled stage. Moreover, the addition of PSF generates a matrix with two-phases that changes in composition and morphology depending on the percent of added thermoplastic and curing temperature as observed by scanning electron microscopy. (c) 2005 Elsevier Ltd. All rights reserved.