Abstract

Abstract

Three new conjugated poly(p-phenylene vinylene) (PPV) derivatives bearing triphenylamine side-chain through a vinylene bridge, poly(2-(4′-(diphenylamino)phenylenevinyl)-1,4-phenylene-vinylene) (DP-PPV), poly(2-(3′-(3″,7″-dimethyloctyloxy)phenyl)-1,4-phenylenevinylene-alt-2-(4′- (diphenylamino)phenylenevinyl)-1,4-phenylenevinylene) (DODP-PPV), and poly(2-(4′-(diphenylamino)phenylenevinyl)-1,4-phenylenevinylene-co-2-(3′,5′-bis(3″,7″-dimethyloctyloxy)-1,4-phenylenevinylene) (DP-co-BD-PPV), were synthesized according to the Gilch or Wittig method. Among the three polymers, the copolymer DP-co-BD-PPV is soluble in common solvents with good thermal stability with 5% weight loss at temperatures higher than 386°C. The weight-average molecular weight (M_w) and polydispersity index (PDI) of DP-co-BD-PPV were 1.83 × 10⁵ and 2.33, respectively. The single-layer polymer light-emitting diodes (PLEDs) with the configuration of Indium tin oxide (ITO)/poly (3,4-ethylenedioxythiophene): poly(4-styrene sulfonate)(PEDOT:PSS)/DP-co-BD-PPV/Ca/Al were fabricated. The PLED emitted yellow-green light with the turn-on voltage of ca. 4.9 V, the maximum luminance of ca. 990 cd/m² at 15.8 V, and the maximum electroluminescence (EL) efficiency of 0.22 cd/A. Copyright © 2007 John Wiley & Sons, Ltd.

Summary: Fabrication of honeycomb-patterned films from amphiphilic dendronized block copolymer (PEO₁₁₃-b-PDMA₈₂) by ‘on-solid surface spreading’ and ‘on-water spreading’ method is reported. Highly ordered honeycomb films with quasi-horizontally paralleled double-layered structure can be fabricated by the on-solid surface spreading method. This work raises the possibility that such structures can be formed in amphiphilic dendronized block copolymers and extends the family of source materials.

Summary: Dendronized poly(methacrylate)-poly(ethylene oxide) (PDMA₅₈-b-PEO₄₅) formed as a stoichiometric inclusion complex with α-cyclodextrin. The incorporation of the rodlike PDMA blocks produced no apparent change in the crystal structure, but its steric hindrance on the PEO chain resulted in lower yield as compared with the pure PEO. Moreover, the architectural transition from rod–coil to rod–rod led to a morphological change from spindly aggregates to rods in a binary solvent mixture of N,N-dimethylformamide and water.

Two novel phenyl-substituted poly(p-phenylene vinylene) derivatives, poly{2-[3′,4′-(2″-ethylhexyloxy)(3″,7″-dimethyloctyloxy)benzene]-1,4-phenylenevinylene} (EDP-PPV) and poly{2-[3′,4′-(2″-ethylhexyloxy)(3″,7″-dimethyloctyloxy)benzene]-5-methoxy-1,4-phenylenevinylene} (EDMP-PPV), and their copolymer, poly{2-[3′,4′-(2″-ethylhexyloxy)(3″,7″-dimethyloctyloxy)benzene]-1,4-phenylene-vinylene-co-2-[3′,4′-(2″-ethylhexyloxy)(3″,7″-dimethyloctyloxy)benzene]-5-methoxy-1,4-phenylenevinylene} (EDP-co-EDMP-PPV; 4:1, 1:1, and 1:4), were successfully synthesized according to the Gilch route. The structures and properties of the monomers and the resulting conjugated polymers were characterized with ¹H-NMR, ¹³C-NMR, elemental analysis, gel permeation chromatography, thermogravimetric analysis, ultraviolet–visible absorption spectroscopy, and photoluminescence and electroluminescence (EL) spectroscopy. The EL polymers possessed excellent solubility in common solvents and good thermal stability with a 5% weight loss temperature of more than 380°C. The weight-average molecular weights and polydispersity indices of EDP-PPV, EDMP-PPV, and EDP-co-EDMP-PPV were 1.40–2.58 × 10⁵, and 1.19–1.52, respectively. Double-layer light-emitting diodes with the configuration of indium tin oxide/polymer/tris(8-hydroxyquinoline)aluminum/Al devices were fabricated, and EDP-co-EDMP-PPV (1:1) showed the highest EL performance and exhibited a maximum luminance of 1050 cd/m² at 19.5 V. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1259–1266, 2005

A novel amphiphilic diblock copolymer, consisting of dendronized polymethacrylate-b-poly(ethylene oxide), was synthesized via atom transfer radical polymerization; from it, micellelike aggregates of various morphologies, prepared under near-equilibrium conditions, were studied with transmission electron microscopy and scanning electron microscopy. The effects of various factors on the aggregate morphologies of the amphiphilic copolymer, such as the water content, the copolymer concentration, and the type of common solvent, were investigated systematically. The unique architecture of the block copolymer led to morphological variety and peculiarities such as dendritic and shuttle-shaped aggregates, which could be attributed to the effective packing of the bulky side chains, that is, another driving force for the aggregates. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2291–2297, 2005

A series of new poly(p-phenylene vinylene) derivatives with different dendritic pendants—poly{2-[3′,5′-bis(2″-ethylhexyloxy)benzyloxy]-1,4-phenylenevinylene} (BE–PPV), poly{2-[3′,5′-bis(3″,7″-dimethyl)octyloxy]-1,4-phenylenevinylene} (BD–PPV), poly(2-{3′,5′-bis[3″,5″-bis(2‴-ethylhexyloxy)benzyloxy]benzyloxy}-1,4-phenylenevinylene) (BBE–PPV), poly(2-{3′,5′-bis[3″,5″-bis(3‴,7‴-dimethyloctyloxy)benzyloxy]benzyloxy}-1,4-phenylenevinylene) (BBD–PPV), and poly[(2-{3′,5′-bis[3″,5″-bis(2‴-ethylhexyloxy)benzyloxy]benzyloxy}-1,4-phenylenevinylene)-co-(2-{3′,5′-bis[3″,5″-bis(3‴,7‴-dimethyloctyloxy)benzyloxy]benzyloxy}-1,4-phenylenevinylene)] (BBE-co-BBD–PPV; 1:1)—were successfully synthesized according to the Gilch route. The structures and properties of the monomers and the resulting conjugated polymers were characterized with ¹H and ¹³C NMR, elemental analysis, gel permeation chromatography, thermogravimetric analysis, ultraviolet–visible absorption spectroscopy, photoluminescence, and electroluminescence spectroscopy. The obtained polymers possessed excellent solubility in common solvents and good thermal stability, with a 5% weight loss temperature of more than 328 °C. The weight-average molecular weights and polydispersity indices of BE–PPV, BD–PPV, BBE–PPV, BBD–PPV, and BBE-co-BBD–PPV (1:1) were in the range of 1.33–2.28 × 10⁵ and 1.35–1.53, respectively. Double-layer light-emitting diodes (LEDs) with the configuration of indium tin oxide/polymer/tris(8-hydroxyquinoline) aluminum/Mg:Ag/Ag devices were fabricated, and they emitted green-yellow light. The turn-on voltages of BE–PPV, BD–PPV, BBE–PPV, BBD–PPV, and BBE-co-BBD–PPV (1:1) were approximately 5.6, 5.9, 5.5, 5.2, and 4.8 V, respectively. The LED devices of BE–PPV and BD–PPV possessed the highest electroluminescent performance; they exhibited maximum luminance with about 860 cd/m² at 12.8 V and 651 cd/m² at 13 V, respectively. The maximum luminescence efficiency of BE–PPV and BD–PPV was in the range of 0.37–0.40 cd/A. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3126–3140, 2005