Synthesis and properties of a novel high-temperature diphenyl sulfone-based phthalonitrile polymer

Abstract

A novel high-temperature diphenyl sulfone-based phthalonitrile polymer is prepared from bis-[4-(3,4-dicyanophenoxy)phenyl]sulfone (BDS) monomer synthesized with high yield by a simple nucleophilic displacement of a nitro-substituent from 4-nitrophthalonitrile (NPN). The structure of BDS polymer is investigated by Fourier transform infrared spectroscopy and wide-angle X-ray diffraction. Curing behavior of BDS monomer with 1,3-bis(4-aminophenoxy)benzene (APB) is recorded by differential scanning calorimetry. The properties of BDS polymer are evaluated by thermogravimetric analysis, dynamic mechanical analysis, and tensile test. The results reveal that the BDS polymer exhibits excellent thermal and thermo-oxidative stabilities, high glass temperature ( Tg = 337°C), and outstanding mechanical properties (Young’s modulus: 4.02 GPa and tensile strength: 64.16 MPa). Additionally, the BDS polymer exhibits high flame retardance and low water uptake.