Synthesis and properties of cross-linkable poly (aryl ether ketone) oligomers terminated with phthalonitrile group

Abstract

Two kinds of phthalonitrile end-capped poly (aryl ether ketone) oligomers (CN- o-PEEK and 2CN- o-PEEK) have been synthesized. The two molecular structures were identified using Fourier transform infrared, nuclear magnetic resonance, and elemental analysis. Hydroxy-containing CN- o-PEEK can be thermal polymerized by duration at 225°C for various times, even in the absence of curing additives. Char yields at 800°C after heat treatment for 60 min were 55%. 2CN- o-PEEK was cured in the presence of p-bis[4-(4-aminophenoxy) phenyl]sulfone via heating its powders up to 275–375°C. The synthesized oligomers have good solubility, whereas the cured samples become insoluble in common organic solvents. The resulting cured samples exhibit no glass transition temperature up to 400°C as measured by differential scanning calorimetry and possess excellent thermal stability.