Synthesis of high glass transition temperature fluorescent polyarylene ether nitrile copolymers

A novel series of fluorescent copolymers were synthesized by the nucleophilic aromatic substitution polymerization of 2, 6-dichlorobenzonitrile with different ratios of phenolphthalein to phenolphthalin. The derived copolymers showed good solubility in common organic solvents at room temperature and good film-forming properties. These copolymers were characterized by Fourier transform infrared, proton nuclear magnetic resonance, ultraviolet–visible absorption, fluorescence spectroscopy, differential scanning calorimetry and thermogravimetric analysis. They had high glass transition temperatures ranging from 237 °C to 260 °C and good thermal stability with the 5% weight loss temperatures in the range of 373–455 °C. Furthermore, the copolymers exhibited characteristic bimodal ultraviolet–visible absorption and unimodal fluorescence emission in both solution and film states.