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Showing 1 to 14 of 14 for “"Poly(p-phenylene)"”.
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Synthesis and characterization of poly-(p-phenylene pyromellitamic acid)
<p>"Poly-(p-phenylenepyromellitamic acid)s have been synthesized over the weight average molecular weight range from 8,000 to 22,000 by reaction of pyromellitic dianhydride and p-phenylenediamine in dimethylformamide. The polymers were recovered as amorphous yellow powders having planar dimensions …
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Crystallization behavior of poly (p-phenylene sulfide): kinetics and morphology
The crystallization behaviour of poly (p-phenylene sulfide) (PPS) has been studied. lsothermal rates of bulk crystallization, spherulitic radial growth rates, and nucleation densities were analyzed as functions of molecular weight of PPS, branching agent concentration, and chemical nature of the …
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Synthesis and applications of electron deficient conjugated polymers
… we present the general properties of conjugated polymers for sensory and electronic applications, with a special emphasis placed on electron-deficient materials. Chapter 2. In this chapter is presented the synthesis, characterization, and applications of a series of electron-deficient …
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Three dimensional molecular architectures for the synthesis and improved properties of high performance polymers
Conjugated polymers have found various uses in optoelectronic applications, including chemical sensors, light-emitting diodes, and photovoltaic materials. In this thesis, we investigate the effect of having a molecular architecture that is both rigid and three-dimensional might play in the …
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Photophysics of Phenylene Vinylene Polymers and Oligomers: The Influence of Nanocrystalline Domains
… of excited states and their photodynamics in phenylene vinylene molecules. Poly-p-(phenylene vinylene) (PPV), poly[(2-methoxy-5-hexyloxy-p-phenylene)vinylene] (MH-PPV), and 1,4-distyrylbenzene (DSB), a small molecule analog of PPV, are studied using various spectroscopic techniques including …
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The interplay of nanostructure and efficiency of polymer solar cells
… a deep understanding of the working mechanism of polymer based solar cells and to improve the device performance. Two types of the polymer based solar cells are studied here: all-polymer solar cells comprising macromolecular donors and acceptors based on poly(p-phenylene vinylene) and hybrid cells …
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A study of processing methods for producing biaxial orientation in thermotropic liquid crystalline polymers
… orientation and properties in two thermotropic copolyesters: hydroxybenzoic acid-co-polyethylene terephthalate (HBA/PET) and hydroxybenzoic acid/2, 6 hydroxynaphthoic acid (HBA/HNA). They consisted of solid phase forming, extrusion blow molding, biaxial stretching, and film blowing. Some measure …
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Light emitting characteristics and dielectric properties of polyelectrolyte multilayer thin films
… sequential adsorption technique to deposit thin polyelectrolyte multilayer films. This involves alternately dipping a substrate into dilute aqueous solutions of a positively charged polyelectrolyte followed by a negatively charged polyelectrolyte, with a rinsing step in between. By repeating this …
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Morphology Effects on the Optical Properties of Phenylene Vinylenes From Nano-Scale to Bulk
… of nano-scale morphology on the spectroscopy of phenylene vinylene molecules. A series of phenylene vinylene oligomers and polymers were synthesized (1,4-distyrylbenzene (DSB), 4,4' -bis-hexyloxy-1,4-distyrylbenzene, 1,4-bis-hexyloxy-2,5-distyrylbenzene, 4,4'-distyrylstilbene, …
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Parylene-based chemical vapor deposition of electroluminescent polymer films used in polymer light emitting diodes
… properties of the conjugated electroluminescent polymer poly(p-phenylene vinylene) (PPV) prepared by parylene-based chemical vapor deposition (CVD) are explored in this thesis. A reactor for CVD of PPV is designed and constructed, and both a,a'-dibromo p-xylene and a,a.'-dichloro p-xylene are …
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Designing Functionality into Step-Growth Polymers from Liquid Crystallinity to Additive Manufacturing
Step-growth polymerization facilitates the synthesis of a wide range of industrially applicable polymers, such as polyesters and polysulfones. The choice of backbone and end group structure within these polymers drastically impacts the final material properties and processability emphasizing the …
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Crystallization behavior and structure property behavior of selected thermoplastic polymers
The crystallization behavior of poly(p-phenylene sulfide) PPS has been studied. Two PPS samples with < M<sub>w</sub> > = 43K and < M<sub>w</sub> > = 83K were fractionated to remove low molecular weight oligomers yielding fractionated PPS samples with < M<sub>w</sub> > = 57K and < Mw > = 113K. The …
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Counterion Distribution around a Macroion in Polyelectrolytes Probed by Anomalous Small-Angle X-ray Scattering
A systematic and comprehensive study of polyelectrolytes in solution has been carried out using Anomalous Small Angle X-ray Scattering (ASAXS) in order to probe the counterion correlation around the macroion. In the course of this study, different polyelectrolyte systems such as, rod-like …
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Synthesis and Characterization of Multiblock Copolymers for Proton Exchange Membrane Fuel Cells (PEMFC)
… hydrophilic-hydrophobic multiblock copolymers are promising proton exchange membrane (PEM) materials due to their ability to form various morphological structures which enhance transport. Four arylene chlorides monomers (2,5-Dichlorobenzophenone and its derivatives) were first …