• Title/Summary/Keyword: Carboxyl groups

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기능성기를 지닌 고분자 자성체를 이용한 수용액 중 납이온 추출

  • 서형석;최규찬;나인욱;황경엽
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.04a
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    • pp.175-176
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    • 2004
  • To develope of efficient method for decontaminating of lead ions from industrial wastewater, treatment of aqueous lead solution with magnetic beads was investigated. Immobilization of carboxyl groups on tile surface of magnetic beads was carried out to introduce chelate effect between lead ions and beads. Experiments were performed with lead solutions and magnetic beads at pH 6. Lead ions were extracted during 1 hour, After extraction, magnetic beads were separated from water by outer magnetic force and the solution was analysed by atomic absorption spectroscopy (AAS). Over 90 % of lead ions could be removed from aqueous solution after beads application. This result indicate that magnetic beads can be used as a efficient method for removing lead ions from industrial wastewater.

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Property of Poly(amic acid) Precursor Solution (Poly(amic acid) 전구체 용액의 성질)

  • Ahn, Young Moo
    • Textile Coloration and Finishing
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    • v.8 no.2
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    • pp.43-48
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    • 1996
  • Condensation type aromatic polyimides were synthesized in DMF solvent by two step low temperature solution polymerization. By employing monomers as p-phenylene 3diamine and 3 kinds of dianhydrides such as pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride and trimellitic anhydride chloride, poly(amic acid) precursors were sythesized. These reactions were exothermic and very fast. When synthesized poly(amic acid)s were dissolved in DMF solvent and stood long time, the polymers were hydrolyzed and their degradation reactions were accelerated as the solution concentrations were dilute. Also, when water is added there-to the degradation rates were accelerated 8faster. In addition, in a very dilute solution state, the reduction viscosity is greatly increased to show properties of conventional polyelectrolytes. This also showed properties sensitive to the concentration change as carboxyl groups per unit segment are increased.

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Analysis of the Surface Degradation in UV-irradiated Poly(ethylene terephthalate) films (자외선 조사된 Poly(ethylene terephthalate) 필름의 표면 열화 분석)

  • Lim, Kyung-Bum;Kim, Jong-Yoon;Choi, Hoon-Young
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.12
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    • pp.2230-2234
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    • 2010
  • This paper deals with the change of surface potential decay, surface resistivity, contact angle and XPS of ultraviolet-treated PET films. From the experimental results on the surface potential decay of UV degraded-samples, it was found that the accumulation of charge is decreased and the surface potential decay time is shortened. Also, from the result of XPS, it was found that the changes affected by the surface degradation of PET film were caused by the generation of carboxyl groups through the chain decomposition and recombination with oxygen molecules in the air.

UV-Cut Effects of Cotton Fabrics Treated with UV Absorbents (자외선 흡수제 처리에 의한 면직물의 자외선 차단 효과)

  • 지영숙;김상희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.18 no.5
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    • pp.622-627
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    • 1994
  • The purpose of this study is to investigate the adsorption rate, adsorption quantities and the UV-Cut effects of cotton fabrics treated with several UV absorbents. The result of this study were as follows: cotton fabric treated with 2,2'-dihydroxy-4- methoxy-benzophenone shows more efficient than ones treated with 4-aminobenzoic acid and 2·hydroxy-1, 4-naphthoquinone in UV absorption. This may be due to the absorption of UV light by formation of intra moleculaar hydrogen bond. The formation of hydrogen bonds between hydrogen atoms of two hydroxy groups and one oxygen atom of carboxyl group in 2, 2'-dihydroxy-4-methoxy-benzophenone would be easier than that of the other absorbents. The adsorption isotherms of 4-aminobenzoic acid and 2-hydroxy-1, 4-naphthoquinone were similar to Freundlich type, while that of 2, 2'-Dihydroxy-4-methoxy-benzophenone was Henry type. Cotton fabrics treated with Antifade MC-100 and W Cut I-2 were just alike in UV absorption, but Antifade 8001 was inferior to the others.

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A Study on the Characteristics of Surface Degradation & Degradation-Mechanism in UV Treated FRP (자외선 파장에 따른 FRP의 표면 열화특성 및 열화메커니즘에 관한 연구)

  • Lee, B.S.;Lim, K.B.;Na, D.G.;Chung, M.Y.;Chung, E.N.;You, D.H.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.813-815
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    • 1998
  • In order to analyse the degradation process of epoxy/glass fiber for outdoor condition, FRP laminate was exposed to the wavelength of ultraviolet rays and evaluated by comparing contact angle, surface resistivity, surface potential decay, and ESCA spectrum respectively. Finally, We can conclude that the degradation phenomena on the surface of epoxy composites are dominated by the induction of ester and carboxyl groups.

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Analysis of the Surface Degradation in UV-irradiated Poly(ethylene terephthalate) films (자외선 조사된 Poly(ethylene terephthalate) 필름의 표면 열화 분석)

  • Lim, K.B.;Lee, B.S.;Hwang, M.H.;Kim, Y.Y.;Lim, H.C.;Chi, C.S.;Nam, K.W.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1457-1459
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    • 2001
  • This paper deals with the change of surface Potential decay, surface resistivity, contact an91e and XPS of ultraviolet-treated PET films. From the experimental results on the surface Potential decay of UV degraded-samples, it was found that the accumulation of charge is decreased and the surface potential decay time is shortened. Also, from the result of XPS, it was found that the changes affected by the surface degradation of PET film were caused by the generation of carboxyl groups through the chain decomposition and recombination with oxygen molecules in the air.

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Titania-assisted dispersion of carboxylated single-walled carbon nanotubes in ZnO sol for transparent conducting films with high thermal stability ($TiO_2$ 도입에 따른 ZnO 졸에서의 단일벽 탄소나노튜브의 분산안정성 및 그 투명전도성 필름의 고온 안정성)

  • Kim, Bo-Gyeong;Han, Joong-Tark;Jeong, Hee-Jin;Jeong, Seung-Yol;Lee, Geon-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.277-277
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    • 2010
  • We present facile chemical route stabilizing dispersion of carboxylated single-Walled carbon nanotubes (SWCNTs) in ZnOsol prepared by using diethanolamine as a stabilizer. The dispersion was stabilized via capping of carboxyl groups on the SWCNT surface by a titania layer. We also demonstrated that the conductivity of the films prepared P3/$TiO_2$/ZnO as enhanced by therml treatment, and the thermal stbility of the film improved hybridization with ZnO sol pristine P3, P3/$SiO_2$ and P3/$TiO_2$ hybrid films.

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Titania-assisted dispersion of carboxylated single-walled carbon nanotubes in ZnO sol for transprent conducting films with high thermal stability ($TiO_2$ 도입에 따른 ZnO 졸에서의 단일벽 탄소나노튜브의 분산안정성 및 그 투명전도성 필름의 고온 안정성)

  • Kim, Bo-Gyeong;Han, Joong-Tark;Jeong, Hae-Deuk;Jeong, Hae-Deuk;Jeong, Seung-Yol;Lee, Geon-Woong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.03b
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    • pp.41-41
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    • 2010
  • We present facile chemical route stabilizing dispersion of carboxylated single-walled carbon nanotubes (SWCNTs) in ZnOsol prepared by using diethanolamine as a stabilizer. The dispersion was stabilized via capping of carboxyl groups on the SWCNT surface by a titania layer. We also demonstrated that the conductivity of the films prepared P3/$TiO_2$/ZnO as enhanced by therml treatment, and thethermal stbility of the film improved hybridization with ZnO sol pristine P3, P3/$SiO_2$ and P3/$TiO_2$ hybrid films.

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Acylation of Wool Keratin with Dibasic Acid Anhydrides - on reaction mechanism - (2염기산 무수물에 의한 양모섬유의 아실화(I) - 반응메카니즘을 중심으로 -)

  • 신은주;박찬헌;최석철
    • Textile Coloration and Finishing
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    • v.7 no.1
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    • pp.65-71
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    • 1995
  • Wool yarns were treated in dimethylformamide solutions containing various concentrations of three dibasic acid anhydrides : succinic, itaconic, and phthalic anhydrides in various conditions. The structural aspects of these dibasic acid anhydrides are different : the succinic, itaconic, and phthalic acid anhydrides have saturated aliphatic etylene, unsaturated aliphatic vinyl and aromatic phenyl groups, respectively. The reaction mechanism of the acylation of wool keratin and some resction conditions were invastigated. And the results are as follows. 1. The N-acylation and formation of free carboxyl group were dominant rather than the O-acylation cross-linked on the side chain of polypeptide. The acylation of wool keratin is easier than that of silk fibroin. 2. The higher molecular weight, steric hinderance and resonance caused lower acylating reactivity. By the determination of acyl contents for acylated keratin, it was rerealed that the degree of acylation was succinic acid anhydride > itaconic acid anhhydride > phthalic acid anhydride.

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Epoxidized Polybutadiene as a Thermal Stabilizer for Poly(3-hydroxybutyrate). II. Thermal Stabilization of Poly(3-hydroxybutyrate) by Epoxidized Polybutadiene

  • Choi, Ju-Yol;Lee, Jong-Keun;You, Young;Park, Won-Ho
    • Fibers and Polymers
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    • v.4 no.4
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    • pp.195-198
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    • 2003
  • Epoxidized polybutadiene (EPB) was prepared by polybutadiene (PB) with m-chloroperbenzoic acid (MCPBA) in homogeneous solution. EPB was blended with poly(3-hydroxybutyrate) (PHB) up to 30 wt% by solution-precipitation procedure. The thermal decomposition of PHB/EPB blends was studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and differential thermal analysis (DTA). The thermograms of PHB/EPB blends contained a two-step degradation process, while that of pure PHB sample exhibited only one-step degradation process. This degradation behavior of PHB/EPB blends, which have a higher thermal stability as measured by maximum decomposition temperature and residual weight, is probably due to crosslinking reactions of the epoxide groups in the EPB component with the carboxyl chain ends of PHB fragments during the degradation process, and the occurrence of such reactions can be assigned to the exothermic peaks in their DTA thermograms.