• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1759-1761
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• 1999

The generation of pretilt in nematic liquid crystal(NLC)and electro-optical(EO) characteristics of photo-aligned twisted nematic (TN)-LCD with oblique p-polarized ultraviolet (UV) light irradiation on the two kinds of the soluble polyimide (PI) surfaces containing trifluoromethyl moieties were investigated. The generated pretilt angle of NLC is about $2.5^{\circ}$ with p-polarized UV light irradiation of $20^{\circ}$ on PI-3 surface at 20 min.; However pretilt angle of about $0.5^{\circ}$ are observed on PI-1 and PI-2 surfaces. The generated pretilt angle of NLC on PI-3 surface may be attributed to the trifluoromethyl moieties attached to the lateral benzene rings. The voltage-transmittance and response time characteristics of photo-aligned TN-LCD with p-polarized UV light irradiation of $20^{\circ}$ on PI-1 surfaceat at 20 min were almost same in comparison with the rubbing-aligned TN-LCD. However, the high threshold voltage and slow response are observed on PI-3 surface. Also, the decay time $\tau_d$ of photo-aligned TN-LCD is attributed to the anchoring energy of NLC.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.343-346
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• 1998

The generation of pretilt angle in nematic liquid crystal (NLC) and electro-optical (EO) characteristics of photo-aligned twisted nematic (TN)-LCD with oblique P-polarized ultraviolet (UV) light irradiation on the two kinds of the soluble polyimide (PI) surfaces containing trifluoromethyl moieties were investigated. The generated pretilt angle of NLC is about 2.5$^{\circ}$with P-polarized UV light irradiation of 20$^{\circ}$on PI-3 surface at 20 min.; However pretilt angle of about 0.5$^{\circ}$are observed on PI-1 and PI-2 surfaces. The generated pretilt angle of NLC on PI-3 surface may be attributed to the trifluoromethyl moieties attached to the lateral benzene rings. The voltage-transmittance and response time characteristics of photo-aligned TN-LCD with P-polarized UV light irradiation of 20$^{\circ}$on PI-1 surface at 20 min were almost same in comparison with the rubbing-aligned TN-LCD. However, the high threshold voltage and slow response are observed on PI-3 surface. Also, the decay time $\tau$$\sub$d/ of photo-aligned TN-LCD is attributed to the anchoring energy of NLC.

• 폴리머
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• 제39권2호
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• pp.275-280
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• 2015

4,4'-Biphthalic anhydride(BPA)와 2,2'-bis(trifluoromethyl) benzidine(TFB)의 구조에 서로 다른 무수물인 4,4'-(hexafluoroisopropylidene) diphthalic anhydride(6FDA)와 1,2,4,5-benzentetra carboxylic dianhydride(pyromellitic dianhydride) (PMDA)를 각각 반응시켜 열적 및 화학적 이미드화 반응을 통해 두 가지 시리즈의 폴리이미드 공중합체(copolyimide, Co-PI)를 합성하였다. 합성한 Co-PI를 각각 다른 두 가지 무수물 단량체의 조성에 따라 열적 성질 및 광학적 투명성을 서로 비교 분석하였다. 열적 성질을 증가시키기 위해서는 6FDA보다는 PMDA가 더 효과적이었으나, 광학 투명성에서는 오히려 6FDA가 더 효과적이었다.

• 농약과학회지
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• 제4권3호
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• pp.15-18
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• 2000

제초제 후보물질로서 N-{2,4-dichloro-5-(N-methylpyrazol-3-yl)phenyl}imides 7과 N-{2,4-dichloro-5-(N-methy-lpyrazol-5-yl))Phenyl}imides 8의 유도체들을 합성하여 제초활성을 온실조건에서 조사하였다. 처리량 1 kg/ha에서 pyrazole moiety에 carboxylate나 carboxamide 치환기가 있는 화합물들 (7c-7l) 제초활성을 나타내지 않았으나, pyrazole moiety에 trifluoromethyl기가 있는 화합물들은 처리량 63-250 g/ha에서 논피, 물달개비, 너도방동산이등의 잡초들에 대해 제초활성을 보였고 벼에 대해서는 안전한 결과를 보였다.

• Macromolecular Research
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• 제16권6호
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• pp.503-509
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• 2008

A series of colorless polyimide (PI) nanocomposite films were synthesized from 2,2'-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFDB) with various organoclay contents by solution intercalation polymerization to poly(amic acid)s, followed by thermal imidization. The variation with the organoclay content of the thermomechanical properties, morphology, and optical transparency of the hybrids was examined at organoclay loadings ranging from 0 to 1.0 wt%. The hybrid films showed high optical transparency and almost no color, with cut-off wavelengths ranging from 352 and 356 nm and very low $b^*$ values of 1.19-1.77. The hybrid PI films showed good thermal properties with a glass transition temperature of $280-287^{\circ}C$. Most films did not show any significant thermal decomposition below $490^{\circ}C$. The addition of only a small amount of organoclay was sufficient to improve the tensile properties of the PI films with maximum enhancement being observed at 0.25 wt% organoclay. Moreover, these PI hybrids also had low coefficients of thermal expansion (CTE).

• 농약과학회지
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• 제5권2호
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• pp.26-32
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• 2001

새로운 농약살균제의 개발을 목적으로 trifluoromethyl기 dihydro-1,4-dithiin기 포함된 ${\alpha},{\beta}$-불포화 carboxamide 유도체 12를 합성하였다. trifluoromethylated ${\beta}$-ketoester 유도체 4를 염화한 다음 1,2-ethandithiol과 반응시켜 중간체 1,4-dithiane 유도체 9를 얻었다. 중간체 9의 정제없이 hydroxy기를 염소로 치환하여 생성된 중간체 8을 triethylamine 존재하에서 탈염화하여 trifluoromethyl기가 포함된 dihydro-1,4-dithiin ethyl ester 7을 합성하였다. Ester 7을 가수분해하여 생성된 carboxylic acid 10의 hydroxy를 염소로 치환하여 활성화한 다음 여러 가지 amine 유도체와 반응시켜 trifluoromethyl기가 포함된 dihydro-1,4-dithiin carboxamide 유도체 12를 합성하였다. 합성된 화합물을 대표적이 6종의 식물병원균, 벼 도열병원균, 벼 잎집무늬마름병원균, 오이 잿빛곰팡이병원균, 토마토 역병원균, 밀붉은녹병원균, 보리 흰가루병원균 등에 대한 항균력을 시험 (in vivo) 하였다. 그 결과, 대부분의 화합물이 미약한 항균을 나타냈다. 페닐기의 meta 위치에 isopropy기가 치환된 화합물 12h는 250 ppm에서 밀 붉은녹병원균에 대한 항균력 (99%)을 나타냈다.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1998년도 가을 학술발표회논문집
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• pp.41-44
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• 1998

Wholly aromatic polybenzoxazoles (PBO) are well established as high performance materials with excellent thermal stability and mechanical properties. Heterocyclic precursor polymers such as polyhydroxyamides (PHA) have been interested in the field of high performance flame retardant polymers. The PHAs can be converted to PBOs when ignited. (omitted)

• Bulletin of the Korean Chemical Society
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• 제29권7호
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• pp.1421-1423
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• 2008

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.130.1-130.1
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• 2003

The metabolism of a novel anticancer agent 1-{3- [3-(4-Cyano -benzyl)-3H-imidazol-4-yl]-propyl }-3-(6-methoxy-pyridin-3-yl)-1-(2-trifluoromethyl-benzyl)-thiourea (YH3945) were investigated in the Sprague-Dawley rat after single oral and i.v. administration of [14C]-YH3945. Bile, feces, urine and plasma were collected and analyzed by an HPLC system equipped with multiple detectors. (omitted)

• Bulletin of the Korean Chemical Society
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• 제26권5호
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• pp.795-801
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• 2005

New PPV derivatives which contain electron-withdrawing trifluoromethyl ($CF_3$) group, poly[2-(2-ethylhexyloxy)-5-(4-trifluoro methylphenyl)-1,4-phenylenevinylene] (EH$CF_3$P-PPV), and poly[2-(2-ethylhexyloxy)-5-(3,5-bis(trifluoromethyl)-phenyl)-1,4-phenylenevinylene] (EHB$CF_3$P-PPV), have been synthesized by GILCH polymerization. As the result of the introduction of the electron-withdrawing $CF_3$ group to the phenyl substituent, the LUMO and HOMO energy levels of EH$CF_3$P-PPV (2.8, 5.1 eV) and EHB$CF_3$P-PPV (3.0, 5.3 eV) were lower than those of known poly[2-(2-ethylhexyloxy)-5-phenyl-1,4-phenylenevinylene] (EHP-PPV) (2.6, 4.9 eV). These polymers have been used as the electroluminescent (EL) layers in double layer lightemitting diodes (LEDs) (ITO/PEDOT/polymer/Al). EH$CF_3$P-PPV, and EHB$CF_3$P-PPV show maximum photoluminescence (PL) peaks at ${\lambda}_{max}$ = 550, 539 nm, and maximum EL peak at ${\lambda}_{max}$ = 545, 540 nm, respectively. The current-voltage-luminance (I-V-L) characteristics of the polymers show that turn-on voltages of EH$CF_3$P-PPV and EHB$CF_3$P-PPV are around 4.0 and 3.5 V, respectively.