This study focuses on the synthesis and characterization of new polyamides based on an aromatic asymmetric diaminecontaining phenoxy-substituted benzophenone segment. Low-temperature solution polycondensation reactions of this diamine with various aromatic diacid chlorides containing ether, hexafluoroisopropylidene or diphenylsilane groups resulted in polyamides with molecular weights in the range 102 900-113 200 g mol −1 . The structures of these monomers and the corresponding polymers were fully confirmed using elemental analysis and infrared and NMR spectroscopy. All polyamides were easily soluble at room temperature in polar aprotic solvents and even in less polar solvents such as tetrahydrofuran. The polymers showed excellent thermal stability, up to 385 • C, and displayed glass transition temperatures in the range 225-256 • C. All the polymers presented blue florescence upon irradiation with UV light and thus show promise for applications in electroluminescent devices.

As majority of polyheteroarylenes based on bis(naphthalic anhydrides), are difficult to process due to their infusiblity and insolubility in common organic solvents and solubility only in strong acids, this study is concerned with the synthesis and properties of new, easily processable polyimides and copolyimides containing naphthalene and oxadiazole rings. These polymers have been synthesized and their properties have been compared with regard to the influence of oxadiazole and naphthalene units on their physical properties. The polyimides were prepared by polycondensation reaction in solution of the aromatic diamines containing preformed oxadiazole ring with two dianhydrides having naphthalene units, at high temperature. Also, copolyimides were prepared by using a mixture of each naphthalene‐containing dianhydride, with hexafluoroisopropylidene‐dianhydride in the polycondensation reaction with the same diamino‐oxadiazoles. Most of the resulting polyimides and copolyimides were soluble in polar amidic solvents and in less polar solvents, and their solutions gave flexible films when spread onto glass plates. The thermal stability and glass transition temperature of these polyimides and copolyimides were measured and compared. The quality and the roughness of the spin‐coated films of these polymers were investigated by atomic force microscopy. The photoluminescence properties of the polymers in solution were studied to determine the color of emission. The UV absorption was also studied to determine the Stokes shift, and hence the possible reabsorption effects. The properties of the present polyimides make them attractive for applications in advanced optoelectronics and other related fields. Copyright © 2009 John Wiley & Sons, Ltd.

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New polyamides containing 1,3,4-oxadiazole and naphthalene rings were prepared by low-temperature solution polycondensation reaction of a new diamine containing preformed oxadiazole ring with various aromatic diacid chlorides. Elemental analysis, mass, infrared, and nuclear magnetic resonance spectroscopy were used to confirm the structure of the monomers and corresponding polymers. The thermal stability and glass transition temperatures of these poly(oxadiazoleamide)s were measured and compared with those of related polymers. Their good solubility allows them to be processed in very thin films with smooth surfaces, without pinholes or cracks, when studied by atomic force microscopy. Upon irradiation with UV light the polymers showed photoluminescence maxima in the blue spectral range, both in solution and in solid state. Cyclic voltammetry (CV) was performed in order to obtain information about the electrochemical stability and reversibility of the redox processes of these polyamides. The highest occupied molecular orbital and the lowest unoccupied molecular orbital energy levels, and electrochemical and optical band gap values were calculated by using the results of CV and UV/vis, respectively, showing very good electron and hole injection and transport characteristics. These properties make the present polymers suitable for application in electroluminescent devices. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: [893][894][895][896][897][898][899][900][901][902][903][904][905][906] 2011 Fully aromatic poly(1,3,4-oxadiazole)s form another class of high performance polymers that are designated for use in small quantities, but with very high end-value. 22 High performances include high thermal resistance in oxidative atmosphere, good hydrolytic stability, tough mechanical properties, optical properties, highly ordered systems, and other special properties determined by the electronic structure of this particular heterocycle. [23][24][25][26] There is currently much interest in high-brightness blue light-emitting diodes to be used in full colour displays, full colour indicators, and light sources for lamps, which have high efficiency and high reliability as characteristics. For such a purpose polyoxadiazoles are very attractive because, due to the electron-withdrawing character of the 1,3,4-oxadiazole rings, they can

Two series of poly(oxadiazole-imide)s based on naphthalene-containing anhydrides and aromatic diamines containing preformed oxadiazole rings have been synthesized and their properties studied and compared. One series contains four polymers: two of them are based on naphthalene-1,4,5,8-tetracarboxylic dianhydride and the other two are based on bis(ketonaphthalicanhydride). The other series contains four copolymers based on mixtures of these dianhydrides with hexafluoroisopropylidenediphthalic anhydride. The thermal stability of these polymers and copolymers and their photo-optical properties in solution and solid state have been investigated.