Synthesis, characterization, and photoresponsive behavior of some polysulfones containing azobenzene moieties in the main chain

New photoactive copolysulfones carrying azo crown ether moieties in the main chain were prepared by polycondensation reaction of 4,4′-bis(4-hydroxyphenylazo)dibenzo-18-crown-6, bisphenol A, and bis(4-chlorophenyl)sulfone. The azo polysulfones were characterized via FTIR and 1H NMR spectra, thermogravimetrical analysis, and differential scanning calorimetry. The products showed good thermal stability, with 10% weight loss temperatures ranging from 366 to 426 °C, while the glass transition temperatures varied from 137 to 158 °C. A kinetic study of trans-cis-trans isomerization process based on the evolution of the electronic absorption spectra during UV irradiation was conducted.