Rheology, morphology, and properties of polyarylene ether nitrile blends

Polyarylene ether nitrile (PEN) blends with different mass ratios of PEN bisphenol (BP) to PEN bisphenol A (BPA) were prepared by solution casting method. The morphological, rheological, thermal, dielectric, and mechanical properties of the resulted blends were systematically studied. Rheological studies show that the addition of PEN (BPA) could improve the flowability of blends except that of 90/10 (BP/BPA). Meanwhile, the crystallization degree of blends also decreases except that of 90/10 (BP/BPA). Mechanical measurement results indicate that the PEN blend (PEN (BP):PEN (BPA) of 90:10) possesses highest tensile strength of 119.7 MPa, increased by 28.6% than PEN blends (PEN(BP):PEN(BPA) of 50:50). Besides, the scanning electron microscopic images show that there exists phase separation in the PEN blends (PEN (BP):PEN (BPA) of 50:50), which is well consistent with the Cole-Cole plots obtained from rheological studies. Moreover, the phenomenon of phase separation will lead to interfacial polarization between the two different phases, which is a significant factor to induce the transformation of dielectric constant. Furthermore, all blends possess high thermal stability (initial decomposition temperature over 470 degrees C) and high mechanical property (tensile strength over 93 MPa), suggesting that PEN blends (BP/BPA) have a good prospect of extension and application.