A new alkoxy substituted phenyl-containing hyperbranched conjugated poly(phenylene vinylene) (Hyper-PMEH-PPV) has been synthesized through the well-known Wittig polycondensation reaction. The synthesized Hyper-PMEH-PPV was completely soluble in common organic solvents and exhibited good thermal stability up to 383 °C. The photophysical properties of Hyper-PMEH-PPV are investigated and compared with a linear conjugated poly(para-phenylene vinylene) (Linear-PMEH-PPV) and well-known MEH-PPV. An absorption maximum of Hyper-PMEH-PPV film was determined at 395 nm which was far blue-shifted than that of Linear-PMEH-PPV (428 nm). Hyper-PMEH-PPV film showed green photoluminescence (PL) peak at 513 nm. In addition, Hyper-PMEH-PPV film exhibited almost no excimer or aggregate emission peaks even when the polymer film was annealed at 80 °C for 30 min in air condition. No undesirable emissions from Hyper-PMEH-PPV film are due to the inhibition of intermolecular interaction by the introduction of the hyperbranched network into the poly(phenylene vinylene) backbone.
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