초록 |
A series of copolymers, poly{(2'-(2-ethylhexyloxy)-5'-methoxy-[1,1';4',1'']-terphenyl-4,4’’-diyl)-co-(2,5-diphenyl-[1,3,4]-oxadiazole-4’,4’’-diyl)}, were synthesized by polymerizing 4,4’’-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-(2'-(2-ethylhexyloxy)-5'-methoxy-[1,1';4',1'']-terphenyl with a series of mixtures of 4,4''-dibromo-2'-(2-ethyl-hexyloxy)-5'-methoxy-[1,1';4',1'']-terphenyl and 2,5-bis-(4-bromophenyl)-[1,3,4]-oxadiazole by palladium-catalyzed Suzuki coupling reaction. The copolymers were characterized using 1H-NMR, FT-IR spectroscopy, DSC, TGA, UV-vis spectroscopy, photoluminescence (PL) spectroscopy, elemental analysis and molecular weight determination. They show relatively good solubility in organic solvents such as chloroform, chlorobenzene, xylene, and 1,1,2,2-tetrachloroethane, etc. They exhibit relatively high glass transition temperatures and also good thermal stability. All the synthesized copolymers showed absorption peak at 360 nm. In the PL spectra of copolymers, however, the emission maxima of the copolymers gradually shift to a longer wavelength from 420 nm to 446 nm as the content of oxadiazole comonomer increases. |