• Applied Chemistry for Engineering
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• v.23 no.6
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• pp.614-617
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• 2012

Ti-containing zeolite was synthesised and used in the epoxidation of di-cyclopentadiene (DCPD). Among various Ti-zeolite catalysts, Y contained Ti-zeolite showed the highest yield in the epoxidation of DCPD. The study was also investigated in terms of the Ti content in the catalysts, $H_2O_2$/substrate ratio, reaction temperature and applied time. The reaction conditions significantly influenced on both the catalytic activity and selectivity. In addition, Ti structure in the zeolite was analyzed using IR and UV-vis spectroscopy.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.11a
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• pp.172-176
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• 1999

에폭시 수지의 강인성 향상을 위하여 양말단에 아민 반응기를 가지는 PES-CTBN-PES triblock copolymer를 합성하여 이를 에폭시 수지의 강인화제로 사용하였으며 경화제로는 p-DDS(p-dichlorodiphenylsulfone)를 사용하였다. 또한 공중합체에 의한 물성 향상효과를 CTBN과 PES-NH$_2$의 블렌드에 의한 경우와 비교하였다. 강인화된 에폭시 수지의 물성은 강인성 및 굴곡특성을 측정하여 분석하였으며, 열특성은 DSC, TGA, 및 DMA에 의해 실시되었다. 그리고 강인화된 에폭시 수지의 강인성 향상 mechanism을 규명하기 위하여 파단면을 SEM으로 분석하여 상분리 거동을 고찰하였다. 높은 유리전이온도와 우수한 기계적 물성을 가지는 고성능 기능성 폴리설폰(PES-NH$_2$)과 상용 액상 고무 첨가제인 CTBN을 이용하여 합성된 공중합체를 강인화제로 사용함으로써 열안정성, 탄성률 및 내식성의 감소없이 에폭시 수지의 쳐대 단점인 강인성을 최적 수준으로 개선시킬 수 있었으며 공중합체의 에폭시 수지에 대한 우수한 용해도에 따른 가공성이 향상되었다.

• Polymer(Korea)
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• v.35 no.1
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• pp.47-51
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• 2011

In this study, illite, an environmental friendly, low cost, and high aspect ratio additive, was used to improve flame retardant property of epoxy and it was fluorinated to enhance dispersion of hydrophilic illite in hydrophobic epoxy by introducing hydrophobic functional groups. Fluorination of illite enhanced illite dispersion ill epoxy solution before curing and that in the complex after curing. These enhanced dispersions were attributed to the increased affinity of illite to hydrophobic epoxy solution induced by fluorination of illite and the increased intercalation of epoxy polymer or exfoliation of illite by epoxy curing. Hence, limited oxygen index(LOI) of fluorinated illite/epoxy complex increased by 24%, compared to that of epoxy, suggesting that the preparation of fluorinated illite/epoxy complex increased their flame retardant properties.

• 한국전기화학회:학술대회논문집
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• 1999.04a
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• pp.27-27
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• 1999

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.665-668
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• 2008

Propylene epoxidation by $H_2O_2$ (30% aqueous) as oxidant was studied in a semi-batch reactor using Ti-MCM-22 catalyst: Effects of reaction temperature, pressure, catalyst loading, solvent, and $H_2O_2$ concentration on $H_2O_2$ conversion (limiting reagent) were investigated. Product inhibition by propylene oxide was confirmed. Ti-MCM-22 maintained virtually the same catalytic performance over the 5 repeated cycles.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.649-656
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• 1992

The synthesis of epichlorohydrin was carried out by the epoxidation of allyl chloride with tert-butyl hydroperoxide(TBHP) over silica supported molybdenum catalyst. Kinetic study was performed at $60-80^{\circ}C$ and 10 atm with the molar ratio of TBHP/Allyl chloride between 0.01 and 0.1 in a batch reactor. The epoxidation of allyl chloride was inhibited by tert-butyl alcohol and kinetic data could be represented by Michaelis-Meten type rate equation. The reaction mechanism could be explained by the combination of reversible adsorption of TBHP and tert-butyl alcohol accompanied by reaction of allyl chloride with TBHP adsorbed on $Mo/SiO_2$ catalyst.

• Clean Technology
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• v.18 no.1
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• pp.51-56
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• 2012

Here, we report an efficient iron complex $[((phen){_2}(H_2O)Fe^{III}){_2}({\mu}-O)](ClO_4){_4}$, that can rapidly epoxidize 1,3-butadiene at $-10^{\circ}C$ with low catalyst loadings by using commercially available peracetic acid as an oxidant. The main aspect of our study is to investigate the effect of temperature (from -10 to $-40^{\circ}C$) and time on the epoxidation reaction. The epoxidation reaction was fast and almost completed within 5 min at temperatures above $-20^{\circ}C$, whereas it became slow at temperatures below $-20^{\circ}C$. The yield of butadiene monoepoxide (BMO)increased with increasing the reaction time. Generally, when the more butadiene was used, the higher yield was obtained. The highest yield of BMO was 90%.

• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.1030-1035
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• 1994

Curing behavior and glass transition temperatures of epoxy resins into which reactive diluents were added to control processability were investigated. Heat of cure generated of the epoxy resin was reduced with butyl glycidyl ether(BGE) and phenyl glycidyl ether(PGE) contents. $T_g$ of the resin was decreased with the amount of reactive diluents and it was attributed to increased molecular weight between crosslink points. Cure kinetics of the resins was studied employing autocatalytic reaction model and found that reaction constants decreased as the contents of reactive diluent was increased.

• Polymer(Korea)
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• v.28 no.5
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• pp.391-396
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• 2004

In order to overcome drawbacks in the conventional preparation of epoxy/silica nanocomposites, such as formation of micro voids and dimensional instability caused by evolution of volatile by-products during curing reaction, a novel preparation method using Si-N precursor has been proposed. When prepared through in-situ reaction of epoxy curing reaction with sol-gel reaction of Si-N precursor, methyltripiperidinylsilane (MTPS) which does not produce by-products during reaction, epoxy/silica nanocomposites of extremely even dispersion of inorganic phase could be successfully prepared, resulting in high enhancement of mechanical and thermal properties as well as outstanding transparency.

• Korean Journal of Materials Research
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• v.5 no.5
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• pp.606-610
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• 1995

Diglycidyll ether of bisphenol A(DGEBA)/4, 4'-methylene dianiline(MDA)계에 반응성 첨가제 malononitrile(MN)을 첨가하면 내충격성은 크게 향상되나 반응속도는 감소하게 된다. 에폭시 수지의 경화반응은 에폭시기가 개환되어 생성되는 히드록시기가 촉매로 작용하는 자촉매 반응이며, 외부에서도입된 히드록시기도 같은 효과를 나타낸다. 따라서 본 연구에서는 DGEBA/MDA/MN 계의경화 반응속도를 증가시키기 위해 히드록시기를 가진 촉매로서 hydroquinone(HQ)을 도입하였고 이들 계의경화특성 및 열적성질을 고찰하였다. HQ가 첨가됨으로 인해 활성화 에너지는 감속하고 속도상수는 증가하였으며, 발열곡선에서 반응 시작온도가 낮아졌다. 이 결과로부터 HQ가 반응 가속제로 작용하고 있음을 알 수 있다.