Effect of curing behaviors on the properties of poly(arylene ether nitrile) end‐capped with phthalonitrile

Abstract

Abstract Poly(arylene ether nitrile) (PEN) end‐capped with phthalonitrile (PEN‐n) was synthesized by incorporating phthalonitrile into the terminals of PEN. The as‐prepared flexible PEN‐n (after elevated temperature treatment) was characterized by infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography, and rheological measurements. In addition, the effects of curing behaviors on properties of PEN‐n films were studied by thermal, dielectric and mechanical measurements. Differential scanning calorimetry analysis showed that glass transition temperature of PEN‐n was improved from 176 to 232°C as the curing temperature and time increased. Thermal gravimetric analysis revealed that initial decomposition temperature of PEN‐n cured at 320°C for 2 h was 570°C. Mechanical properties showed that tensile strength of PEN‐n uncured and cured at 320°C for 3 h was 85 and 97 MPa, respectively. The dielectric properties showed that the dielectric constant of PEN‐n film decreased from 4.0 to 3.1 as the curing time increased and dielectric loss of PEN‐n was 0.01 at 100 kHz. This kind of PEN‐n film may be used as a good candidate for high‐performance polymeric materials. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012