Synthesis and Blue Light Emitting Properties of Meta- and Para-Linked Hyperbranched Polymers Containing Oxadiazole Unit

摘要

Two meta-and para-linked hyperbranched polymers containing oxadiazole unit (end-capped by carbazole unit) (E-Hyper-MOXPPV and E-Hyper PDXPPV) were synthesized through the Wittig polycondensation polymerization. Both polymers showed excellent solubility in common organic solvents and exhibited good thermal stability up to 350 degrees C. An absorption maximum of E-Hyper-MOXPPV film was determined at 298 nm which was far blue shifted than that of E-Hyper-PDXPPV film (349 nm). Light emitting properties of E-Hyper-MOXPPV and E-Hyper-PDXPPV in solution and net solid film are investigated and compared each other. E-Hyper-MOXPPV and E-Hyper-PDXPPV films showed blue photoluminescence (PL) peaks at 451 nm and 478 nm, respectively. Both polymers exhibited almost no excimer or aggregate emission even the films were annealed at 80 degrees C for 1 hr in air condition. No aggregate and excimer emission are due to inhibition of intramolecular or intermolecular interaction by the introduction of hyperbranched network into the meta-and para-linked oxadiazole containing poly(phenylene vinylene) backbone.