New aromatic polyethers containing phenylquinoxaline and 1,3,4-oxadiazole rings

A series of new heterocyclic polyethers, containing phenylquinoxaline and 1 ,3,4-oxadiazole rings. was synthesized by polycondensation of bis (4-fluoro phenyl)-1,3,4-oxadiazole with a diphenol containing preformed phenylquinoxa line rings. These polymers showed good solubility in chloroform and gave tr ansparent, flexible films, by casting their solutions onto glass plates. Th ey exhibited glass transition temperatures in the range of 225-337 degreesC and were stable when heated up to 420 degreesC, the initial decomposition temperature being in the range of 425-465 degreesC. Solutions of these poly mers in chloroform exhibit violet fluorescence, having maximum emission wav elength in the range of 412-425 nm and fluorescence quantum yield in the ra nge of 0.11-0.26. The polymer films displayed a low dielectric constant and tough mechanical properties. (C) 2001 Elsevier Science Ltd. All rights res erved.