Effect of nanosilica on the thermal, mechanical, and dielectric properties of polyarylene ether nitriles terminated with phthalonitrile

Nanosilica/polyarylene ether nitriles terminated with phthalonitrile (SiO 2 /PEN‐ t ‐Ph) composites were prepared by hot‐press approach. To ensure the nano‐SiO 2 can disperse uniformly, the solution casting method combined with ultrasonic dispersion technology had been taken previously. The mass fraction of nano‐SiO 2 particles was varied to investigate their effect on the thermal, mechanical, and dielectric properties of the nanocomposites. From scanning electron microscope images, it was found that the nanoSiO 2 particles were dispersed uniformly in the PEN‐ t ‐Ph matrix when the addition of nano‐SiO 2 was less than 16.0 wt%. However, when the mass fraction of nano‐SiO 2 increased to 20.0 wt%, the nano‐SiO 2 particles tend to self‐aggregate and form microns sized particles. Thermal studies revealed that nano‐SiO 2 particles did not weaken the thermal stabilities of the PEN‐ t ‐Ph matrix. Mechanical investigation manifested that the SiO 2 /PEN‐ t ‐Ph nanocomposites with 12.0 wt% nano‐SiO 2 loading showed the best mechanical performance with tensile strength of 108.2 MPa and tensile modulus of 2107.5 Mpa, increasing by 14% and 19%, respectively as compared with the pure PEN‐ t ‐Ph film. Dielectric measurement showed that the dielectric constant increased from 3.70 to 4.15 when the nano‐SiO 2 particles varied from 0.0 to 20.0 wt% at 1 kHz. Therefore, such composite was a good candidate for high performance materials at elevated temperature environment. POLYM. COMPOS., 35:344–350, 2014.