• Textile Coloration and Finishing
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• v.19 no.6
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• pp.35-38
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• 2007

FTriphenylamine dye compound having diheteryl moiety was synthesized and its photoluminescent property was investigated. Organic luminescent materials have received great attentions due to potential application subjects onto full color image displays. In this context, the dye (III) for light emitting materials was synthesized using 2-(4-amino-2-hydroxyphenyl)benzoxazole (I) and 4,4'-diformyltriphenylamine (II). It is well known that the amino groups of compound (I) react with carbonyl groups, especially an aldehyde, to afford azomethine linkages. The dye shows bulish-green fluorescence property, which is anticipated for the light-emitting material for display devices. In this context, our aim is to synthesize diheteryl-substituted triphenylamine fluorescent dye as an emitting material. The spectroscopic characteristics and the fluorescent properties of this dye molecule were examined and determined.

• Elastomers and Composites
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• v.54 no.4
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• pp.321-329
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• 2019

A series of poly(hyroxyamide)s (PHAs) was prepared by direct polycondensation reaction of 4,4'-(2,3-pyridinedioxy)dibenzoic acid and/or isophthalic acid with 3,3'-dihydroxybenzidine. The yield percentages of the products were high, and the inherent viscosities of the polymer in DMAc solution at 35℃ were 0.31-0.59 dL/g. All PHA polymers were found to be soluble in polar aprotic solvents such as DMAc, DMSO, NMP, and DMF. On the other hand, LiCl was required to dissolve IPHA-1 in aprotic solvents. Poly(benzoxazole)s (PBOs) were partially soluble in conc-H₂SO₄; IPBO-4, -5, and -6 were partially soluble in NMP only when LiCl was added to the solution, and the solution was heated. The PBO polymers showed a maximum weight loss in the temperature range of 654-680℃, and the char yields at 900℃ under nitrogen atmosphere exceeded 63%.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.2865-2866
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• 2009

• Bulletin of the Korean Chemical Society
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• v.30 no.4
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• pp.873-881
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• 2009

Bis(phenylethynyl)dimethylsilane is branched by the hydrosilation of the phenylethynyl group with dichloromethylsilane, and then the resulting chlorosilane is reacted with lithium phenylacetylide to give the $1^{st}$ generation. The same hydrosilation and alkynylation are repeated to obtain the $7^{th}$ generation. In addition peripheral Si-Cl moiety of the seven kind generation dendrimers are reacted with alcoholic moiety of 9-hydroxymethylanthracene and 2-(2-hydroxyphenyl)benzoxazole group in the presence of TMEDA. Then three kinds of carbosilane dendrimers are prepared from the $1^{st}$ to the $7^{th}$ generations, the $7^{th}$ generation of each dendrimer has 256 phenylethynyl, 256 9-anthracenylmethoxy, or 128 2-(2-phenoxy)benzoxazole groups. Each synthesized dendrimer is unequivocally characterized by $^1H\;and\;^{13}C\;NMR$, elemental analysis, MALDI-MS, GPC, and PL (photoluminescence). Characteristically PDI (Polydisperse Index) values of the dendrimers’ peak in GPC are in the range of $1.00{\sim}1.07$, which indicates that each generation of carbosilane is in unified distribution. PL spectra of phenylethynyl and 9- anthracenemethoxy group substituted dendrimers show no significant change with increasing the generation from the $1^{st}$ to the $7^{th}$. However, the PL spectra of 2-(2-phenoxy)benzoxazole group substituted dendrimers show a blue-shift trend with increasing the generation from the $1^{st}$ to the $7^{th}$.

• Bulletin of the Korean Chemical Society
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• v.23 no.1
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• pp.17-18
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• 2002

• Analytical Science and Technology
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• v.11 no.4
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• pp.292-296
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• 1998

Normal phase or reversed phase liquid chromatographic separation of isoquinoline of heterocyclic compounds and structural isomers of external substituents, $COOCH_3$, CN and $CH_3$ has been carried out by using several different columns and various mobile phases. From this results, the order of elution of heterocyclic compounds appears to depend on the solvent effect with kinds of mobile phases. Retention mechanism of normal phase system for 2-methylindoline, 2-methylindole, benzoxazole and benzothiazole was also studied depending on adsorption strength between solute and stationary phase of column. However, retention factors of reversed phase system were found on hydrophobic interaction with solvophobic effect.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.23-24
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• 2006

We have synthesized electroluminescence materials. including [2-(2-hydroxyphenyl)benzoxazole] (Zn(HPB)$_2$), [(2-(2-hydroxyphenyl)benzoxazole)(8-hydoxyquinoline)] (Zn(HPB)q) and [(1, 10-phenanthroline)(8-hydroxyquinoline)] Zn(phen)q. The ionization potential (IP) and electron affinity (EA) of each Zn-complex was measured using cyclic-voltammetry (C-V). Basing on the consideration of matched in the energy levels of the materials. We investigated the electron transporting properties of Zn(HPB)q and Zn(phen)q compared with $Alq_3$, and also we investigated the hole blocking properties of Zn(HPB)$_2$, compared with BCP. As a result, we used Zn-complex to enhance the performance of OLED. Therefore, we demonstrate that Zn(HPB)q and Zn(phen)q are useful as an electron transporting material. Zn(HPB)$_2$ is also good a hole blocking material.

• Elastomers and Composites
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• v.50 no.2
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• pp.138-145
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• 2015

A series of wholly aromatic poly(hydroxyamide)s(PHAs), containing varying amounts of 2,6-dimethylphenoxy group and quinoxaline ring in the main chain, were synthesized by a direct polycondensation method. The inherent viscosities of the PHAs in either DMAc or DMAc/LiCl solution at $35^{\circ}C$ were found to be in the range of 1.02~1.90 dL/g. In the solubility study, we observed that PHA 1, PHA 2, and PHA 3 were dissolved in aprotic solvents such as DMAc, NMP, DMF, and DMSO with LiCl on heating; however, PHA 4, PHA 5, and PHA 6 could be dissolved in aprotic solvents on heating without LiCl. For poly(benzoxazole)s(PBOs), the 10% and maximum weight loss temperatures were in the range of $582{\sim}622^{\circ}C$ and $630{\sim}659^{\circ}C$, respectively. Residues of PBOs at $900^{\circ}C$ were found to be relatively high, which were in the range of 65.3~70.8%.

• Elastomers and Composites
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• v.53 no.3
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• pp.141-149
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• 2018

A series of aromatic poly(o-hydroxyamide)s (PHAs) were synthesized by the direct polycondensation reaction of 4,4′-(2,3-quinoxalinedioxy) dibenzoic acid and/or 4,4′-(2,3-pyridinedioxy) dibenzoic acid with bis(o-aminophenol) including 2,2-bis-(amino-4-hydroxyphenyl)hexafluoropropane. The PHAs exhibited inherent viscosities in the range of 0.17-0.35 dL/g at $35^{\circ}C$ in a DMAc solution. These polymers showed low inherent viscosities and yielded brittle films. All the PHAs showed excellent solubility in aprotic solvents such as DMAc, DMSO, NMP, and DMF at room temperature and in less polar solvents such as pyridine and THF. However, all the PBOs were only partially soluble in $H_2SO_4$. The PBOs exhibited 10% weight loss at temperatures in the range of $537-551^{\circ}C$. The maximum weight loss temperature increased with an increase in the content of the quinoxaline-containing monomer. The residue of the PBOs showed a weight loss of 45.8-56.7% at $900^{\circ}C$ in a nitrogen atmosphere.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.416-417
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• 2006

Organic light emitting diodes (OLEDs) show a lot of advantages for display purposes. Because OLEDs provide white light emission with a high efficiency and stability, it is desirable to apply OLEDs as an illumination light source and back light in LCD displays. We synthesized new emissive materials, namely [2-(2-hydroxyphenyl)benzoxazole] ($Zn(HPB)_2$) and [(2-(2-hydroxyphenyl)benzoxazole)(8-hydoxyquinoline)] (Zn(HPB)q), which have a low molecular compound and thermal stability. We studied white OLEDs using $Zn(HPB)_2$ and Zn(HPB)q. The fundamental structures of the white OLEDs were ITO/PEDOT:PSS (23 nm)/NPB (40 nm)/$Zn(HPB)_2$ (40 nm)/Zn(HPB)q (20 nm)/$Alq_3$ (10 nm)/LiAl (120 nm). As a result, we obtained a maximum luminance of $15325\;cd/m^2$ at a current density of $997\;mA/cm^2$. The CIE(Commission International de l'Eclairage) coordinates are (0.28, 0.35) at an applied voltage of 9.75 V.