Novel soluble aromatic poly(amideimide)s containing 9,9-diphenylfluorene moieties: characterization and optical properties

A series of aromatic poly(amideimide)s containing 9,9-diphenylfluorene moieties and the amide units in the main chain have been synthesized by solution polycondensation reaction of newly prepared diamidedianhydride with several aromatic diamines: 1,3-phenylenediamine, 3,3′-dimethoxy-biphenyl-4,4′-diamine, 4,4′-oxydianiline, 4,4′-(1,3-phenylenedioxy)dianiline, 4,4′-(9-fluorenylidene)dianiline and 1,5-diaminonaphthalene. Molecular structures of the polymers obtained have been characterized using ¹³C NMR, ¹H NMR and FTIR spectroscopies. The polymers prepared are readily soluble in aprotic polar solvents, and form optically transparent films by solution casting. The resultant poly(amideimide)s have been analyzed by differential scanning calorimetry (DSC), thermogravimetry (TG) and wide-angle X-ray diffraction measurements. They exhibited high levels of thermal stability, with decomposition temperatures in the range 452–494 °C, and high glass transition temperatures (181–278 °C). The optical behavior of these polymers has been investigated in NMP solution as well as in the films. The photoluminescence (PL) spectra of the free-standing films prepared from the poly(amideimide)s exhibited maximum emission bands around 506–525 nm in the green region.