부산대학교 도서관

The photochemical reaction of N-ethylcarbazole (EtCz) and carbon tetrabromide (CTB) yields a dye of EtCz trimer (similar to triphenylmethane dye) by a multi-step reaction of EtCz with CTB. In the current study, we applied the principles of this reaction to polymer systems of poly [2-(9-carbazolyl) ethyl methacrylate] (PCzEMA) with CTB. The irradiation of PCzEMA film doped with CTB (CTB/PCzEMA) induced the dimerization between two Cz chromophores, which was monitored by the increase of absorption at 670nm. Since the reactive intermediate of Cz that was substituted with CBr2 was stable, the rate of dimerization gradually accelerated as the sample was allowed to warm in the dark. The CTB/PCzEMA system does not form a trimer of Cz chromophores which is similar to triphenylmethane dye, but the dimerization reaction of the chromophoric groups resulted in photocrosslinking of the PCzEMA film. Then, the photosensitivity of CTB/PCzEMA film was compared with CTB/polyvinylcarbazole and polyvinyl cinnamate films through irradiation with a carbon arc lamp.