• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.129-132
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• 1998

지금까지 면직물의 DP가공에 가장 많이 쓰여온 가교제로는 셀룰로오스의 히드록시기와 ether결합을 형성하는 DMDHEU(dimethyloldihydroxyethylene urea) [1] 이나, 인체에 암을 유발시킬 수 있는 포름알데히드를 발생하기 때문에 그 사용이 제한되고 있으며 현재는 셀룰로오스의 히드록시기와 ester형의 가교를 형성하는 polycarboxylic acid와 같이 포름알데히드를 발생하지 않는 가교제에 대한 연구가 활발히 진행되고 있다. (중략)

• Membrane Journal
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• v.19 no.4
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• pp.310-316
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• 2009

The degradation characteristics of cross-linked lactide/hyaluronic acid (LA/HA) membranes were investigated for purpose of applying to tissue engineering. The lactide/hyaluronic acid cross-linked with 1,3-butadiene diepoxide (BD) and 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) was degradated in deionized water in water bath at $37^{\circ}C$. As the LA/HA mole ratio or crosslinking agent concentration decreased, the degradation rate of the crosslinked membranes increased. In order to investigate the structure change of the membrane in the degradation process, the control sample and 3, 6, 9 days-degradated samples were analysed by the nuclear magnetic resonance spectroscopy. In case of the membranes crosslinked with EDC, the HA-EDC bonding structure was degradated slowly whereas the HA-LA bonding structure was degradated quickly and dissappeared completely after 6 days. In case of the membranes crosslinked with BD, all the crosslinked bonding structure degradated slowly. The HA-BD bonding structure maintained its original state about 89, 83% in case of 3, 6 days-degardated samples respectively whereas the HA-LA bonding structure maintained its original state about 83, 65%. The scanning electron microscopy of the degradated membranes showed that the pore density in the surface, and the structure in the surface and cross section, of the before and after-degradation membranes did not change greatly, so the membranes was shown to be applied to materials for tissue engineering.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.271-275
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• 2005

본 연구결과, ${\beta}$-CD의 재활용을 위해 adipic acid로 ${\beta}$-CD를 가교시킨 후, 우유의 콜레스테롤 제거 실험에 사용한 결과, 10회 재활용하는 동안 평균 89.90%의 콜레스테롤이 제거되었으며, 이에 따른 가교화 ${\beta}$-CD의 재활용률은 97.30%로 나타났다. 재활용에 따른 가교화 ${\beta}$-CD의 수율은 8회 재활용할 때까지 감소폭이 매우 적었으며, 가교화 ${\beta}$-CD의 구조 역시, 8회 재활용할때까지는 ${\beta}$-CD간의 가교결합이 유지되다가 이후부터는 대부분 powder ${\beta}$-CD 형태로 존재하는 것으로 관찰되었다. 재활용하는 동안 콜레스테롤 제거가 가능한 ${\beta}$-CD를 정량한 결과, 8회 재활용할 때까지 일정한 수치를 유지하는 것으로 나타났다. 위 실험 결과, adipic acid로 가교시킨 ${\beta}$-CD를 이용하여 우유의 콜레스테롤 제거 시, 여러 번 사용하여도 가교화 ${\beta}$-CD의 물리적 성질에 변화가 거의 없이 자체의 특성을 유지하는 것으로 보아, 이를 유가공 산업에 적용 시, 경제적인 효과가 매우 클 것이라고 사료된다.

• Journal of Adhesion and Interface
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• v.9 no.2
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• pp.24-31
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• 2008

In this work, calcium hydroxide and magnesium carbonate as metal ionic crosslinking agents were used to introduce ionic crosslinking points to the ethylene vinylacetate (EVA) emulsions for the enhancement of water resistance and mechanical properties of emulsion films. The properties of EVA emulsion film were investigated in crosslinking density, thermal features, surface energy, and mechanical properties, such as tensile strength, elongation at break and tear strength. With the increasing content of metal ionic crosslinking agent, the crosslinking density of the EVA emulsion film increases, resulting into the improvement of water resistance. The surface energy and mechanical properties of the EVA emulsion film, however, showed somewhat different behaviors. The highest surface energy, tensile strength, and tear strength were observed when 0.4% for calcium hydroxide and 0.5% for magnesium carbonate was added respectively, because the EVA emulsion containing carboxylic acid forms strong carboxylate-metal bond of ionically-crosslinked system. Therefore, it can be concluded that metal ionic crosslinking agents, such as magnesium carbonate and calcium hydroxide are considered to improve water resistance and mechanical properties of the EVA emulsion.

• Membrane Journal
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• v.28 no.5
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• pp.326-331
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• 2018

Crosslinking of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) anion exchange membranes, which can be used for capacitive deionization (CDI), was investigated. PPO Anion exchange polymer was prepared through bromination and amination reaction steps and crosslinked with bisphenol A diglycidylether (BADGE), m-phenylenediamine (m-PDA), and hexamethylenediamine (HMDA). The gelation time by crosslinking was short in the order of HMDA > m-PDA > BADGE. The anion exchange membranes crosslinked at room temperature over a certain amount of crosslinking agent did not dissolve in an aprotic solvent such as 1-methylpyrrolidone (NMP) and the chemical durability of their membranes to organic solvent increased. The ion exchange capacity and water uptake of anion exchange membranes crosslinked with different crosslinker (BADGE) contents were measured and compared. The CDI performance of the crosslinked PPO anion exchange membrane immersed in the HMDA solution was almost the same as that of the non - crosslinked membrane except for the initial stage of the adsorption step.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1570-1574
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• 2008

Various mechanical test were conducted on conventional and crosslinked ultra-high molecular weight polyethylene(UHMWPE) all prepared from the same lot of medical grade GUR 1050 for artificial joint. The conventional materials were not irradiated and treated by heating. The cosslinked materials were irradiated with $25kGy{\sim}200kGy$ by gamma-ray andthen annealed or remelted. Gamma-ray irradiation and heat treatment process were found to significantly impact the crystallinity, and hence the mechanical behavior, of the highly crosslinked UHMWPE. The radiation dose and heating conditions were key predictors of the uniaxial yielding, plastic flow, and failure properties of conventional and highly crosslinked UHMWPE. The correlation model from experiments would be the basic information to enhance the were resistance of artificial joint liner.

• Membrane Journal
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• v.15 no.1
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• pp.8-14
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• 2005

The hyaluronic acid (HA) with excellent biocompatibility can be combined with the monomer polylactide with good biodegradability to produce biocompatible materials which can control the period of degradation in a human body. By freeze drying method, HA and the lactic acid, monomer of polylactide, or lactide, the ester dimer of polylactide, were crosslinked with crosslinking agent, l-ethyl-3-(3-dimethyl aminopropyl) carbodiimide. The analysis of infrared spectroscopy showed that the ester linkage was formed and the analysis of nuclear magnetic resonance (NMR) spectroscopy showed that the ester linkage was due to the reaction of lactic acid and HA. The conversion (6∼32%) and degree of crosslinking (4∼19%) increased but the selectivity was almost constant at 62% as the mole ratio of LA to HA increased from 1 to 10 in the crosslinking reaction. The brittleness became more pronounced and the rate of degradation became faster with more addition of lactic acid resulting from the higher ratio of LA to HA, and the swelling ratio was in the range of 500 to 2000%.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.423-424
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• 2003

셀룰로스 직물은 easy care 성능을 부여하기 위하여 가교제로 처리된다. 현재 공업적으로 가장 많이 이용되고 있는 DMDHEU와 같은 N-methyol 가교제는 공정 중 또는 처리된 제품의 저장 중에 발암물질인 포름알데하이드를 유리시키는 경향이 있어 포름알데하이드를 유리시키지 않는 가교결합제의 개발이 활발하게 연구되고 있다. 이러한 비포르말린계 가교제 중 글리옥살은 그 성능은 매우 뛰어나지만 DP 처리시 사용되는 촉매인 aluminium sulfate는 처리직물의 강도저하와 황변을 일으키는 단점을 지니고 있다[1]. (중략)

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.84-87
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• 2003

셀룰로즈 직물은 easy care 성능을 부여하기 위하여 가교제로 처리된다. 현재 공업적으로 가장 많이 이용되고 있는 DMDHEU와 같은 N-methyol계 가교제는 공정 중 또는 처리된 제품의 저장 중에 발암물질인 포름알데하이드를 유리시키는 경향이 있어 포름알데하이드를 유리시키지 않는 가교결합제의 개발이 활발하게 연구되고 있다. 이러한 비포르말린계 가교제 중 글리옥살은 그 성능은 매우 뛰어나지만 DP 처리시 사용되는 촉매인 aluminium sulfate는 처리직물의 강도저하와 항변을 일으키는 단점을 지니고 있다[1]. (중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.433-440
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• 2016

Composite membranes were prepared by the solution casting method from sulfonated poly(etheretherketone)(sPEEK) and imidazole and phosphotungstic acid(PWA) to enhance the electrolytic properties of the membrane. TGA measurements showed that physical crosslinking due to acid-base interactions improved the thermal resistance to the desulfonation of sulfonic acid groups of the composite membrane and the addition of PWA enhanced the resistance to thermal decomposition of the composite membrane. The acid-base interaction decreased the water uptake, proton conductivity and methanol permeability of the sPEEK/imidazole composite membranes. The addition of PWA increased the proton conductivities while it decreased the water uptake and methanol permeability of sPEEK/imidazole/PWA composite membranes. Therefore, the selectivity of the composite membranes was enhanced by the addition of PWA.