Preparation and characterization of a self‐catalyzed fluorinated novolac‐phthalonitrile resin

A self‐catalyzed fluorinated novolac‐phthalonitrile resin was synthesized by nucleophilic substitution reaction between fluorinated novolac oligomer and 4‐nitrophthalonitrile. Structure of the final product was characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance. With the introduction of fluorine into the backbone, the fluorinated novolac‐phthalonitrile presented elevated performance. Compared with the analogous novolac‐phthalonitrile resin, the dielectric constant of the cured fluorinated resin decreased from 3.30 to 3.15, and the dielectric loss effectively decreased from 0.012 to 0.004 at the frequency of 1 MHz. Furthermore, the fluorinated novolac‐phthalonitrile resin possessed a broader processing window and higher thermo‐oxidative stability than the analogous novolac‐phthalonitrile resin. Consequently, the fluorinated novolac‐phthalonitrile resin may be a good candidate for matrix of high performance composite in electronic and aerospace industries.