Annealing behavior and thermal stability of nanoporous polymer films based on high-performance Cyanate Ester Resins

The present study discloses the annealing behavior and thermal stability of nanoporous film materials based on Cyanate Ester Resins (CERs) obtained by the chemically induced phase separation technique through the use of porogenic molecules of different sizes and concentrations. Measurements were performed by means of thermogravimetric analysis in dynamic and isothermal modes as well as by Fourier Transform Infrared Spectroscopy. Isothermal annealing in the temperature range from 50 to 150 °C led to mass losses observed at temperatures far below the glass transition. Such mass losses were associated with desorption of moisture/water and residual porogen molecules trapped in the bulk. Therefore, these processes were described by diffusion laws, and the values of the basic kinetic parameters were determined. The results were correlated to the structure of the nanoporous CER-based networks derived from the extraction of different porogen molecules. Further, thermal-oxidative degradation occurred in the glass transition temperature domain (expected between 220 and 250 °C) during isothermal annealing at 250 °C.