• Macromolecular Research
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• v.13 no.1
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• pp.14-18
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• 2005

Under irradiation in a microwave oven, six novel poly(amide-imide)s containing tetrahydropyrimidinone, tetrahydro-2-thioxopyrimidine moieties and trimellitic rings in their main chains were synthesized through the polycondensation reaction of N,N'-(4,4'-diphenylether)bis(trimellitimide) diacid chloride with six different derivatives of tetrahydropyrimidinone and tetrahydro-2-thioxopyrimidine in the presence of a small amount of a polar organic medium, such as o-cresol. The polycondensation proceeded rapidly and completed within 7-9 min, producing a series of new poly(amide-imide)s in high yield that showed inherent viscosities in the range 0.33-0.52 dL/g. These poly(amide-imide)s were characterized by elemental analysis, viscosity measurement, thermal gravimetric analysis, solubility test, and FT-IR spectroscopy. All of the polymers were soluble at room temperature in polar solvents such as N,N-dimethylacetamide, N,N-dimethylformamide, dimethylsulfoxide, tetrahydrofuran, and N-methyl-2-pyrrolidone.

• Journal of Integrative Natural Science
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• v.6 no.4
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• pp.211-214
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• 2013

In this study, in order to investigate how consecutive treatments of glass surface with HF acid and water vapor/Ar plasma affect the quality of 3-aminopropyltriethoxysilane self-assembled monolayer (APS-SAM), poly(3,4-ethylenedioxythiophene) (PEDOT) thin films were vapor phase-polymerized immediately after spin coating of FeCl3 and poly-urethane diol-mixed oxidant solution on the monolayer surfaces prepared at various treatment conditions. For the film characterization, various poweful tools were used, e.g., FE-SEM, an optical microscope, four point probe, and a contact angle analyzer. The characterization revealed that HF treatment is not desirable for the synthesis of a high quality PEDOT thin film via vapor phase polymerization method. Rather, sole treatment with plasma noticeably improved the quality of APS-SAM on glass surface. As a result, a highly dense and smooth PEDOT thin film was grown on uniform oxidant film-coated APS monolayer surface.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.820-822
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• 2008

Pentacene has excellent semi-conducting characteristics. But pentacene practically used in OTFTs gives rise to problems mainly due to its sensitivity to oxygen and its very low solubility. In order to make up the problems, 6,13-disubstituted pentacene derivative was synthesized and characterized. The properties of the compound were characterized by FT-IR, NMR and we measured the charge transport mobility and the on/off current ratios.

• Polymer(Korea)
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• v.34 no.6
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• pp.547-552
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• 2010

Biodegradable polymers have gained enormous attentions in the pharmaceutical and biomedical applications, especially in drug delivery. In this work, we report the synthesis and characteristics of high molecular weight polyoxalate with ~75000 Da. Hydrolytic degradation kinetics and degradation products were characterized by nuclear magnetic resonance and gel permeation chromatography. Polyoxalate is a semicrystalline and thermally stable polymer with a glass transition temperature of ${\sim}35^{\circ}C$, which is suitable for drug delivery applications. The hydrophobic nature of polyoxalate allows it to be formulated into nanoparticles and encapsulate drugs using a conventional oil-in-water emulsion/solvent displacement method. Polyoxalate nanoparticles also exhibited excellent cytotoxicity profiles. It can be suggested that polyoxalate has great potential for numerous biomedical and pharmaceutical applications.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.92-92
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• 2003

poly(trimethylene terephthalate) (PTT) was synthesized via condensation polymerization using different molar ratios of 1,3-propane diol (PDO)/terephthalic acid (TPA) in the presence of tetraisopropyl titanate (TiPT) as a polyesterifi-cation catalyst. The effect of reaction conditions on the characteristics of as-polymerized PTT was investigated.

• Macromolecular Research
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• v.11 no.6
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• pp.458-466
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• 2003

Several copolyimides have been synthesized with different combinations of comonomers in order to study the relationship between conductivity and water insolubility. m-Phenylenediamine (m-PDA), an angled comonomer, was introduced into the polymer backbone to increase water absorption, and resulted in higher proton conductivity. 2,2-bis(trifluoromethyl)benzidine (TFMB) was used as the comonomer to promote water insolubility. There is a good correlation between the water uptake and conductivity of the polyimides. The copolyimides that had high water uptake also generated high proton conductivity. Those polyimides had good mechanical properties. The copolyimides that have 27 mol% of TFMB and 9 mol% of m-PDA have reasonable conductivities and are insoluble in water at 90$^{\circ}C$, even though they have lower conductivities than those of the homopolymer.

• Macromolecular Research
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• v.12 no.6
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• pp.604-607
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• 2004

We report an important and useful method for preparing ${\omega}-sulfonated$ polystyrene-stabilized cadmium sulfide (CdS) nanoclusters. The ${\omega}-sulfonated$ polystyrene $(M_n\;=\;5000\;g/mol)$ was prepared successfully through chain-end sulfonation of poly(styryl)lithium using 1,3-propanesultone; the resulting polymer was used successfully as a polymeric stabilizing agent for the preparation of semiconductor CdS nanoclusters by reduction of cadmium acetate in a mixture of toluene and methanol (9:1, v/v). The nanoclusters that formed were characterized by a combination of transmission electron microscopy, X-ray diffraction, and UVN is spectroscopic analysis. The ${\omega}-sulfonated$ polystyrene-stabilized CdS nanoclusters synthesized in this study exhibited the cubic phase (zinc-blende phase) structure in the range of 2-8 nm.

• Journal of Photoscience
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• v.12 no.2
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• pp.95-100
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• 2005

We have synthesized an azobenzene-containing polymer (PEA) and a stilbene-containing polymer (PAS) with second-order nonlinear properties. The second harmonic coefficient ($d_{33}$) of the poled polymer films was 84 and 36 pm/V for of PEA and PAS, respectively. The poled state of these polymers was stable at least up to 30 h at room temperature. $T_g$ of these polymers appeared in the range from 120 to $160^{\circ}C$ and onset of initial weight losses in the range from 260 to $270^{\circ}C$. Silicon moieties in the main chain enhanced the solubility of PEA and PAS in common organic solvents such as chloroform, N-methylpyrrolidinone (NMP), N, N-dimethylformamide (DMF), etc.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.255-255
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• 2006

Polymeric nanoparticles are recognized as promising drug carriers [1]. Here, novel tri-block copolymers based on poly PPDO, PCL and PEG were synthesized and employed for the formulation of reproducible polymeric nanoparticles [2]. To estimate the feasibility of the polymer to form polymeric nanoparticles, nanoparticles were prepared by co-solvent evaporation technique. Polymerization and structural features of the polymer were analyzed by different physico-chemical techniques. Existence of hydrophobic domains as a core of nanoparticles was characterized by $^{1}H-NMR$ spectroscopy, and further confirmed by fluorescence technique using pyrene as probe.

• Macromolecular Research
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• v.13 no.6
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• pp.499-505
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• 2005

Ordered mesoporous materials with a hydrothermally-stable, protozeolitic framework were prepared by exploring the direct conversion of inorganic species based on co-surfactant templating systems. To confer hydrothermal stability on the mesoporous aterials, the organic-inorganic hybrids were heat-treated in strongly basic media. Co-surfactant templating systems of cetyltrimethylammonium bromide [$C_{16}H_{13}(CH_{3})_{3}$NBr, CTAB] with 1,3,5-trim­ethylbenzene (TMB) or a nonionic block copolymer of poly(ethylene oxide )-b-poly(propylene oxide )-b-poly(ethyl­ene oxide) ($EO_{20}PO_{70}EO_{20}$) were employed to improve the hydrothermal stability of the organic-inorganic self-assembly during the solid rearrangement process of the inorganic species. The mesoscopic ordering of the pore structure and geometry was identified by X-ray diffraction, small angle neutron scattering and electron microscopy.