The relationship between processing and performances of polyarylene ether nitriles terminated with phthalonitrile/trifunctional phthalonitrile composites

A novel series of polyarylene ether nitriles terminated with phthalonitrile/trifunctional phthalonitrile (PEN-Ph/TPh) composite films were prepared via solution casting method. The effects of concentration of TPh and prepolymerization treatment as well as curing treatment on the performance of the PEN-Ph/TPh composite films were studied systematically. SEM images shows that the morphology of the composites transformed from phase separated state to homogeneous phase through the prepolymerization and curing treatment, due to the crosslinking reaction between the TPh and the PEN-Ph matrix resin. Moreover, the formation of phthalocyanine rings and triazine rings through crosslinking reaction resulted in the favorable enhancement of thermal, mechanical, and dielectric properties of the PEN-Ph/TPh composites. The glass transition temperature (T-g) of films were promoted from 197 degrees C to 248 degrees C and the temperature corresponding to 5 % weight loss (T-5%) increased by 20 degrees C. The mechanical testing results showed that the tensile strength was enhanced by 30 %, from 92 MPa to 119 MPa. Furthermore, the dielectric constant of composite films increased because the phthalocyanine rings formed via crosslinking reaction and the maximum value reached to 5.40 at 1 KHz.