Preparation and physical properties of polyarylene ether nitrile and polyarylene ether sulfone random copolymers

Polyarylene ether nitrile sulfone (PENS) random copolymers consisting of polyarylene ether nitrile (PEN) and polyarylene ether sulfone (PES) were prepared from bisphenol A, bis(4-chlorophenyl)sulfone, and 2,6-dichlorobenzonitrile by the nucleophilic aromatic substitution polymerization. The structure of the PENS random copolymers was confirmed by Fourier transform infrared spectrometer and H-1 nuclear magnetic resonance, and the properties of the PENS copolymers were investigated by thermal analysis (differential scanning calorimetry and thermogravimetric analysis), inherent viscosity measurements, mechanical tests, and dielectric tests. The samples showed excellent thermal stability, with the 5% weight loss temperature (T-5%) greater than 480 degrees C under nitrogen and glass transition temperature (T-g) greater than 180 degrees C. The tensile strength, tensile modulus, and elongation at break of the PENS copolymers were improved with the increase of the PEN content, indicating the better mechanical property of PEN than that of PES. The dielectric constant and dielectric strength of the PENS random copolymers were also enhanced with the increase of the PEN content. As a result, PENS100 showed the highest energy storage density, which is 0.68 J/cm(3). PES showed better thermal properties while worse mechanical and dielectric properties compared with PEN. PENS copolymers combined the excellent properties of PEN and PES due to the compatibility between them.