• Bulletin of the Korean Chemical Society
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• 제31권8호
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• pp.2279-2282
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• 2010

In this work, the electrical and thermal properties of polyimide/multi-walled carbon nanotube (MWNT) nanocomposites were investigated. The polyimide/MWNT nanocomposites contained from 0 to 2.0 wt % of MWNT. The electrical properties of the polyimide films were characterized by a specific resistance measurement. The thermal properties were evaluated using thermogravimetric analysis (TGA) and a differential scanning calorimeter (DSC). It was found that the thermal properties of the polyimide nanocomposites increased with increasing MWNT content and specific resistance as well. This result indicated that the crosslinking of polyimide/MWNT nanocomposites was enhanced by good distribution of the MWNT in the polyimide resins, resulting in the increase of the electrical and thermal properties of the nanocomposites.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.533-536
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• 2008

The anthracene derivatives were synthesized by Suzuki coupling reaction. The thermal, optical and electronic properties of MNAn and BIPAn were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry(DSC), UV-vis absorption, photoluminescen ce spectroscopies, and cyclic voltammetry. The materials exhibit high thermal stability and high per formance in EL devices.

• 한국전기화학회:학술대회논문집
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• 한국전기화학회 2001년도 연료전지심포지움 2001논문집
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• pp.189-192
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• 2001

In order to prepare the proton-conducting membrane with lower cost and higher ionic conductivity than commercialized one, the concept of incorporating the nitrogen acid to polymer backbone, is proposed. The synthesis, thermal, and temperature-variable impedance/electrical conductivity studies of poly (p-tolunesulfonylamido acrylate) are reported. This polymer can be prepared by reacting poly (acryloyl chloride) with ptolunesulfonamide and cast into homogeneous membranes. Thermogravimetric analysis (TGA) shows that the polymer is thermally stable up to about $200^{\circ}C$ and Differential scanning calorimetry (DSC) illustrates that the glass transition occur at around $67^{\circ}C$. The ionic conductivity measured by dielectric spectroscopy is in the range of $10^{-5}\;S/cm$ in dry atmosphere that it can be a candidate for the membrane of PEMFC or DMFC.

• 한국전기전자재료학회논문지
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• 제14권7호
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• pp.595-599
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• 2001

The mechanisms of pretilt angle generation for a nematic liquid cystal (NLC) using a photodimerization method with obliquely polarized UV exposure on the various new photo-crosslinkable polymer were studied. A good thermal stability of all the photo-crosslinkable polymers was obtained by thermogravimetric analysis (TGA) measurement until 450$\^{C}$. High pretilt angle of the NLC was observed by polarized UV exposure on the three kinds of the photo-crosslinkable polymers containing biphenyl(BP), decyl(de), and cholesteryl(chol) group, respectively. However, the low pretilt angle of the NLC was measured by obliquely polarized UV exposure on the two kinds of the photo-crosslinkable polymers containing fluorine and chalcone group. Consequently, the high NLC angle generated is attributable to the biphenyl and alkyl moieties, and photo-dimerized chalcone group of the photopolymer.

• 한국환경과학회지
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• 제14권10호
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• pp.973-978
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• 2005

Biodegradable oil gelling agent was prepared, and their oil absorption capacities using light oil, lubricant oil and corn oil were investigated. The result showed that the oil absorption capacity was depended on the amount of surfactant and starch added, and was increased in the order of light oil, lubricant oil and corn oil. Also, the oil-absorption capacity was saturated within 30 min at $18^{\circ}C$. The biodegradability of the prepared biodegradable oil gelling agent was also studied by determination of reduced sugar produced after enzymatic hydrolysis. Their surface morphologies and thermal properties of the prepared biodegradable oil gelling agent were observed by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA), respectively.

• 한국환경과학회지
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• 제14권3호
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• pp.359-366
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• 2005

Starch was crosslinked with epichlorohydrin. Crosslinked starch-filled waterborne acrylate (CSWAC) films were prepared by blending this crosslinked starch with waterborne acrylate. The thermal and mechanical properties of these films were investigated by thermogravimetric analysis (TGA), tensile strength and elongation test. The biodegradability was also studied by determination of reduced sugar products after enzymatic hydrolysis and the surface morphology was investigated by scanning electron microscopy (SEM). The CSW AC film showed significantly higher tensile strength and elongation than those of starch-filled waterbonre acrylate (SWAC). The biodegradability of this film was higher than that of native starch-filled acrylate film, and was increased by the addition of crosslinked starch to the acrylate film.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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• pp.180-183
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• 2003

In this work. a potential inexpensive epoxy resin. epoxidized soybean oil (ESO) was synthesized and applied as a toughening agent for 4.4'-tetradiglycidyl diaminodiphenyl methane (TGDDM). The chemical structure of ESO was characterized by FT-IR, $^1H NMR, and ^{13}C NMR$ spectroscopy. The curing behaviors. thermal stabilities. fracture toughness. and flexural strength of TGDDM/ESO blend systems were investigated by using the dynamic DSC. thermogravimetric analysis (TGA). and flexural tests. The thermal stabilities of TGDDM/ESO blend systems were decreased with increasing ESO contents. whereas the critical stress intensity factor ($K_{IC}$) and flexural strength ($\sigma_f$) were increased with ESO contents up to 10 wt% ESO.

• Macromolecular Research
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• 제14권4호
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• pp.424-429
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• 2006

The synthesis of a series of poly(POSS-NBE-b-MTD) copolymers was successfully accomplished, taking advantage of sequential, ring-opening, metathesis block copolymerization using $RuCl_2(=CHPh)(PCy_3)_2$ catalyst. By using cyclopentyl-POSS-norbornene (POSS-NBE) monomer as the first block in the block copolymer, living poly(POSS-NBE) with controlled molecular weight and narrow molecular weight distribution was produced. Then, poly(POSS-NBE-b-MTD) copolymers were successfully prepared, in which sequential monomer addition of methyltetracyclododecene (MTD) to the living poly(POSS-NBE) chain ends was utilized to achieve quantitative crossover efficiency. Characterization by $^1H$ NMR spectroscopy and GPC confirmed the high definition and structural integrity of the poly(PO$S-NBE-b-MTD) copolymers. Thermal properties-and morphologies of the POSS-containing block copolymer nanocomposites were also investigated by using thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and wide-angle X-ray scattering (WAXS).

• Macromolecular Research
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• 제9권5호
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• pp.247-252
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• 2001

Tricyclic aliphatic dianhydride monomer, tricycle[4.2.2.0]dec-9-ene exo, endo-3,4: 7,8-tetra-carboxylicdianhydride (TCDDA), was synthesized by photochemical reaction and poly(amic acid)s from TCDDA and diamines such as 1,4-bis-(4-aminophenoxy)benzene (BAB), 2,2-bis(4-(4-aminophenoxy) phenyl) propane (BAPP), 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane (BAPHF), bis(4-(4-ami-nophenoxy) phenyl)sulfone (BAPS), and 1,4-bis-(4-aminophenoxy)biphenyl (BABP) were prepared. The inherent viscosities of the poly(amic acid)s were between 0.39 and 0.50 dL/g. The poly(amic acid)s were converted to polyimide films by thermal imidization. The glass transition temperatures (T$\_$g/) of the polyimides were in the range of 201-263$\^{C}$. The thermogravimetric analysis (TGA) thermogram of these polyimides showed the temperatures of 5% weight losses between 375 and 393$\^{C}$ in nitrogen atmosphere. To show their utility for image generation, degradations of these polyimides in UV exposure were investigated by UV spectroscopy.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.475-478
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• 2002

VA-LCDs is widely used for recent LCD productions owing to good viewing angle and high contrast. To apply for VA-LCDs, we have synthesized novel homeotropic alignment materials, which all generated high pretilt angles ($9^{\circ}$). The thermal stabilities of them were observed by thermogravimetric analysis (TGA). Transmittances of the NLC cell used the new alignment material were not changed before and after thermal annealing at $120^{\circ}C$ for 24hrs. In this work, the synthesis and alignment properties of new homeotropic alignment materials will be reported.