Synthesis and luminescence properties of novel phenyl-substituted poly(p-phenylene vinylene) derivatives

Three novel phenyl-substituted poly(p-phenylene vinylene) (PPV) derivatives, BDP-PPV, BDMP-PPV, and BDP-co-BDMP-PPV (1:1), have been successfully synthesized according to the Gilch route. The structures and properties of the monomers and the resulting polymers were characterized by using 1H, 13C NMR, elemental analysis, GPC, TGA, UV-vis absorption spectroscopy, photoluminescence (PL) and electroluminescence (EL) spectroscopy. The EL polymers possess excellent solubility in common solvents, good thermal stability with 5% weight loss temperature of more than 370 °C, and higher photostability. The number-average molecular weight (Mn) and polydispersity index (PDI) of the polymers were in the range of (1.52-2.53) × 105 and 1.22-1.36, respectively. Double-layer light-emitting diodes (LEDs) with the configuration of ITO/polymer/Alq3/Al devices revealed that the copolymer, BDP-co-BDMP-PPV (1:1), possessed the highest luminescence properties, which exhibited maximum luminance of up to 3850 cd/m2 at 23.5 V, and maximum luminescence efficiency of up to 2.68 cd/A.