Fabrication of crosslinked single-component polyarylene ether nitrile composite with enhanced dielectric properties

Crosslinked single-component polyarylene ether nitrile (CSC-PEN) composites were fabricated and improved dielectric properties of the CSC-PENS were obtained. Polyarylene ether nitrile was synthesized through the condensation polymerization between hydroquinone, bisphenol A and 2,6-dichlorobenzonitrile, and then terminated with phthalonitriles (PEN-Ph) by reacting with 4-nitrophthalonitrile. Single-component polyarylene ether nitrile (SC-PEN) composites were obtained through the isothermal crystallization at 280, 300, 310, 320 and 340 degrees C, respectively. The CSC-PENS were prepared through post self-crosslinking of SC-PEN at 320 degrees C for 2, 4, 6 and 8 h, respectively. The CSC-PENS were characterized by FTIR, UV-Vis, DSC, XRD, POM, SEM and gel content measurements. Results showed that crystallinity and gel fraction of CSC-PENS is higher than 49.0% and 90.0% respectively. In addition, the PEN crystals are wrapped in its crosslinked network. Compared with PEN-Ph, CSC-PENS showed higher dielectric constant and more stable permittivity with the changing of frequency and temperature. The fabrication CSC-PENS provides a new method for the preparation of high temperature dielectrics.