Synthesis and characterization of new, soluble polyazomethines bearing fluorene and carbazole units in the backbone and solubility-improving moieties in the side group

Abstract

A series of novel, soluble polyazomethines bearing fluorene and carbazole moieties in the main chain and solubility-improving moieties in the side group (dibutyl, ethylhexyl, thienylethyloxy, furyl, and fluorenyl) were synthesized. Good-quality films of these polymers were prepared through the conventional solution-casting and drying processes. Depending on the polymer structure, some polymers showed a glass-transition temperature (107-167 degreesC) and others showed a melting temperature (285-341 degreesC). The temperature of 5% weight loss under nitrogen atmosphere of the polymers ranged from 370 to 464 degreesC. The results indicated that the side groups incorporated into the polyazomethine structure in this work improved the polymer solubility without sacrificing thermal stability. Depending on the polymer structure, some of the polymers were crystalline whereas others were amorphous. All the polyazomethines were solution-processable and thermally stable, making them potential candidate materials for applications in microelectronics and aerospace. Moreover, the features in the UV-visible spectra of the polyazomethines were redshifted as compared with those of the monomers from which the polymers were synthesized, indicating that these polymers, if combined with an appropriate doping agent to improve the light-emitting-and conducting abilities, may be good candidate materials for optoelectronic devices. (C) 2004 Wiley Periodicals, Inc.