• 접착 및 계면
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• 제17권2호
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• pp.49-55
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• 2016

본 연구는 식품연포장 적층 라미네이트에 주로 사용되는 유성접착제를 대체하기 위해 아크릴 수성화방법을 활용하여 친환경적인 수성 점착제를 설계하였다. 방법으로는 음이온/비이온 그리고 인산에스테르 계면활성제들의 조합과 분자량조절제(chain transfer agent, CTA)의 양을 달리하고, 기능성단량체(functional monomer)의 종류를 달리하였다. 합성된 점착제의 가교 정도와 분자량의 영향을 각각 실험군 8종으로 점착제를 설계 합성하고 조사하였다. 그리고 별도로 분자량이 서로 다른 styrene/alpha-methyl styrene/acrylic acid (SAA) semipolymer 분산제(Mw = 13,000과 Mw = 8,600)를 기존의 계면활성제를 대신하여 사용해 감압점착제(Pressure Sensitive Adhesive, PSA)의 물성을 조사하였다. 합성된 10종의 감압점착제가 유연포장용 기본 물성 규격에 적합한지를 DSC, 입자크기, adhesion, 분자량의 물성 분석으로 평가하였다. 실험 결과 계면활성제는 음이온/비이온 조합으로, CTA는 0.2%로 기능성 단량체는 HEA, GMA를 사용한 점착제 2개의 실험군에서 유연포장에 적용 가능한 분자량과 유연성, 낮은 접착력, 작은 입자의 물성을 확인하였다.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.334-334
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• 2006

Helical polymers like polyisocyanates with single screw sense are essential to exhibit sophisticated functions like molecular recognition, self-replication, chirality memory and catalytic activity. One approach that has not been explored is the effect on handedness of the polyisocyanates through end-capping with a chiral residue. Induction of chirality in poly(n-hexyl isocyanate) was studied by end-capping with chiral (R and S) 2-bromo-3-methylbutyryl chloride(R-BMBC and S-BMBC). We have shown that a control over living anionic polymerization of HIC by using a suitable initiator affords an opportunity to introduce chiral end-groups with 100% yield and in high purity. This has resulted in helicity induction through extended lengths several orders of magnitude.

• Macromolecular Research
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• 제17권12호
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• pp.1010-1014
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• 2009

Monodispersed microparticles with a poly(D,L-lactide-co-glycolide) (PLGA) core and a poly(ethyl 2-cyanoacrylate) (PE2CA) shell were prepared by Shirasu porous glass (SPG) membrane emulsification to reduce the initial burst release of doxorubicin (DOX). Solution mixtures with different weight ratios of PLGA polymer and E2CA monomer were permeated under pressure through an SPG membrane with $1.9\;{\mu}m$ pore size into a continuous water phase with sodium lauryl sulfate as a surfactant. Core-shell structured microparticles were formed by the mechanism of anionic interfacial polymerization of E2CA and precipitation of both polymers. The average diameter of the resulting microparticles with various PLGA:E2CA ratios ranged from 1.42 to $2.73\;{\mu}m$. The morphology and core-shell structure of the microparticles were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The DOX release profiles revealed that the microparticles with an equivalent PLGA:E2CA weight ratio of 1:1 exhibited the optimal condition to reduce the initial burst of DOX. The initial release rate of DOX was dependent on the PLGA:E2CA ratio, and was minimized at a 1:1 ratio.

• Macromolecular Research
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• 제11권3호
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• pp.163-171
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• 2003

For the pervaporation of water-ethanol mixtures, new composite membranes having poly(acrylic acid)-poly (butyl methacrylate-co-methyl methacrylate) interpenetrati ng polymer network [PAA-P(BMA-co-MMA) IPN] skin layer supported on porous and crosslinked poly(BMA-co-MMA) were prepared. The morphology of the sub-layer of the composite membrane prepared in the presence of 60 wt% solvent showed cellular structure, on the other hand that of sublayer prepared in the presence of 70 wt% solvent presented very porous interconnected pore structure with macrovoids. Permeation rates of the composite membranes were largely influenced by the morphology of the sublayer. Separation factors increased with the increase of the degree of crosslinking of the PAA network. It was found that permeation rates could be increased by introducing anionic charges on carboxyl groups of the PAA. The permeation rate changes of the PAA-P(BMA-co-MMA) IPN composite membranes according to the feed compositions showed quite similar pattern with the swelling behavior in water-ethanol mixtures.

• 한국염색가공학회지
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• 제14권2호
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• pp.94-94
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• 2002

A number of studies have been introduced on the use of quaternary cationic agents having various reactive groups, which can improve the substantivity of anionic dyes, specially direct dyes, towards cotton. In the case of direct dyes, it is well known that they are widely used due to their convenience to apply and low cost, whilst they display poor levels of fastness properties to washing. Thus many applications using direct dyes in the textile fields have been still enjoyed in the areas where a higher level of wet fastness is specially not required. This work herein comprises that in order to improve the substantivity of direct dyes towards cotton, cellulose-reactive allylamine polymer namely, triazinyl N,N′-dimethyl-N,N′-diallyl ammonium chloride was prepared and treated onto cotton to provide cationic properties within substrates. This application showed that even low concentration of electrolytes being present, the direct dyes were exhausted well on the cationized cotton and that the rate of dye uptake by treated cotton was faster than that of untreated sample. Furthermore the antimicrobial properties were observed from the cationized samples.

• 한국산학기술학회논문지
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• 제5권2호
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• pp.103-107
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• 2004

산업폐수중 anion인 chromate(CrO4-²)처리에 필요한 기능성소재로 이온교환 및 흡착기능을 가진 PAN계 이온교환섬유를 제조하고 성능평가를 실시하여 소재특성을 연구하였다. Poly(acrylonitrile)섬유와 diethyletriamine을 /sup AlCl₃ 촉매 하에서 반응시켜 poly (acryloamidino diethylenediamine)을 제조하고, /sup 13/C-NMR분석으로 확인하였다. 온도에 따른 polymer의 개질반응 정도를 FT-IR 분석으로 조사하여 개질반응의 최적 온도 120℃를 확인하였다. 개질반응된 polymer의 chromate 최대 흡착량을 분석하고, 음이온 흡착에 대한 소재특성을 pH별로 실시하였다. poly(acryloamidino diethylenediamine)/CrO4-² coordinaion 과정의 FT-IR spectra 분석하여 분자내, 분자간 결합형태를 밝히고 coordination된 구조를 제시하였다.

• 폴리머
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• 제26권4호
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• pp.516-522
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• 2002

4급 암모늄기를 관능기로 갖는 아민화 아크릴계 이온교환섬유를 이용하여 연속식 흡착공정 중 linear alkylbenzene sulfonate(LAS)의 흡착특성을 확인하였다. 아민화 아크릴계 이온교환섬유의 LAS흡착성능은 온도가 증가함에 따라 증가하였으며 $40^{\circ}C$에서 최적 흡착성능을 나타내었다. 또한 컬럼 베드 충진비(L/D)의 변화에 따른 LAS 이온의 흡착능은 L/D>2에서 최대 흡착능을 나타내었다. pH 변화에 따른 LAS이온 흡착능은 pH가 증가함에 따라 증가하는 경향을 나타내었고, pH 7에서 최대 흡착능을 나타내었다. 유속변화에 따른 LAS 흡착능은 유속이 증가할수록 낮아졌으며 농도가 높을수록 떨어졌다.

• 상하수도학회지
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• 제24권5호
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• pp.485-493
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• 2010

Chemical coagulation destabilizes colloidal particles so that particles grow to larger flocs. Solid particles are then removed by solid-liquid separation after typical precipitation. Rapid precipitation enhances the separation by reducing the precipitation time with larger and denser particles. Conventionally, polyelectolyte compounds (polymers) function as a flocculant aid by introducing a interparticle binding, which increases the particle size and density. And more recent ballasted flocculation adds a ballasting agent (microsand) to form denser particles with its high-density(sp gr=2.65). The current research was to evaluate the manner in which ballasted flocs are formed under different injection timings of microsand and to recognize the effects on floc formation. $FeCl_3$ as a coagulant, anionic polymer for a flocculation aid and microsand were used for the floc formation. Floc size (diameter) was widely ranged with the highest mean value when microsand was injected between $FeCl_3$ and polymer. Mean floc density was larger when the floc formed smaller. Settling velocity increased with larger floc size, whilst not significantly affected by the timing of microsand injection. The additional slow mixing on floc formation increased floc size to some extent.

• 폴리머
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• 제26권5호
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• pp.575-581
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• 2002

본 연구는 폴리에틸렌 기재에 비드와 섬유상 이온교환체의 배합비를 달리하여 불균질 이온 교환막을 제조하였다. PE 불균질 이온교환막의 이온교환능은 섬유강 이온교환체의 양이 증가할수록 선형적으로 증가하였으며 30 wt%에서 최대 1.86 meq/g 이었다. 불균질 이온교환막의 함수율, 고정이온농도 및 이온운반율도 섬유상 이온교환체의 양이 증가할수록 증가하였나. 반면 불균질 이온교환막의 전기저항은 섬유상 이온교환체의 양이 증가할수록 감소하였으며, IXF (ion exchange fiber)의 혼합량이 30 wt%에서 5$\Omega$/$\textrm{cm}^2$으로 전기저항 값이 가장낮았다.

• 상하수도학회지
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• 제30권6호
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• pp.663-671
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• 2016

Coagulation/precipitation process has been widely used for the removal of phosphate within domestic wastewater. Although Fe and Al are typical coagulants used for phosphate removal, these have some shortages such as color problem and low sedimentation velocity. In this study, both Fe and Al were used to overcome the shortages caused by using single one, and anionic polymer coagulant was additionally used to enhance sedimentation velocity of the precipitate formed. Batch experiments using a jar test were conducted with real wastewater, which was an effluent of the second sedimentation tank in domestic wastewater treatment plant. Response Surface Methodology was used to examine the responsibility of each parameter on phosphate removal as well as to optimize the dosage of the three coagulants. Economic analysis was also done on the basis of selling prices of the coagulants in the field. Phosphate removal efficiency of Fe(III) was 30% higher than those of Fe(II). Considering chemical price, optimum dosage for achieving residual phosphate concentration below 0.2 mg/L were determined to be 18.14 mg/L of Fe(III), 2.60 mg/L of Al, and 1.64 mg/L of polymer coagulant.