Synthesis and Characterization of Di-hexyl-fluorene and Triphenylamine Based Copolymers Containing 1,3,4-Oxadiazole Pendants

π-Conjugated polymers, poly(N-(4-(5-(4-tert-butylphenyl)-1,3,4-oxadiazol-2-yl)phenyl)-4-(9,9-dihexyl-9H-fluoren-2-yl)-N-phenyl-benzenamine (TPAOXDPF) and poly(N-(4-butylphenyl)-4-(9,9-dihexyl-9H-fluoren-2-yl)-N-phenylbenzenamine) (TPAPF), were synthesized for light emitting diode application. The electron transporting unit, conjugated 1,3,4-oxadiazole, is attached on the main chain as a pendant. The copolymers were thermally stable up to 393°C. The electroluminescent (EL) device based on TPAOXDPF (ITO/TPAOXDPF/Al) has an efficiency of 0.018 cd/A, which is significantly higher than that of the device based on TPAPF (ITO/TPAPF/Al) (0.008 cd/A). This is due to that 1,3,4-oxadiazole pendants improve the electron transporting properties in the emissive layer.