• Membrane Journal
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• v.24 no.2
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• pp.100-106
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• 2014

In this work, soluble polyimides were synthesized and characterized from 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (DOCDA) and two diamines such as 4,4'-diaminodiphenylether (ODA), 1,4-phenylenediamine (p-PDA). Their thermal properties were analyzed with differential scanning calorimeter (DSC). The gas permeability coefficients (P) and ideal selectivity for $CH_4$ and $CO_2$ of the prepared polyimide membranes were measured with a time-lag apparatus. DOCDA-ODA, DOCDA-p-PDA showed good permeability and selectivity; the permeabilities of $CO_2$ was 6.10, 0.74 barrers and the selectivity of $CO_2/CH_4$ were 67.03, 46.25, respectively. Therefore, DOCDA-ODA showed good possibility as gas separation membrane.

• Polymer(Korea)
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• v.34 no.6
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• pp.495-500
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• 2010

Crosslinked PI films were synthesized from 4,4'-(hexafluoro isopropylidene)diphthalic anhydride (6FDA) and bis[4-(3-aminophenoxy) phenyl] sulfone(BAPS) with various ratios of the reactive monomer cis-4-cyclohexene-1,2-dicarboxylic anhydride(CDBA). We prepared crosslinked poly(amic acid) (PAA) using a 0.1 wt% Grubbs catalyst as a crosslinking agent. The crosslinked PAA was heat-treated at different temperatures to give PI films. The thermo-mechanical properties and optical transparency of the PI films were investigated. The thermal properties of the PI films were examined using Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry(DSC), thermogravimetric analysis(TGA), thermo-mechanical analysis(TMA), and universal tensile machine(UTM), and their optical transparencies were investigated using UV-vis. spectrophotometry. The thermomechanical properties of the PI films improved with increasing CDBA content. However, the optical transparency of the PI films decreased slightly with increasing CDBA content.

• Applied Chemistry for Engineering
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• v.18 no.2
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• pp.116-120
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• 2007

The synthesis of 1-[2-(3-{7-oxabicyclo[4.1.0]heptyl} 1,1,3,3-tetramethyl-disiloxane (Mono), which is a key intermediate for the synthesis of monomers applied for photopolymer systems based on the cationic ring opening polymerization, was studied. Mono was successfully synthesized by the hydrosilylation reaction of 4-vinyl-1-cyclohexene 1,2-epoxide (VCHO) with an excess amount of 1,1,3,3-tetramethyldisiloxane (TMDS) in the presence of a Speier catalyst. The structure and the purity of Mono were characterized by FT-IR, $^1H-NMR$, and $^{29}Si-NMR$. The optimum conditions for the hydrosilyation reaction were found to be 1:4 molar ratio of VCHO to TMDS and 5 ppm of the catalyst at the temperature of $55^{\circ}C$.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.519-524
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• 1997

As an investigation for utilization of ascidian tunic carotenoids as a food color additives, we attempted to collect the volatile thermal degradation compounds from ascidian tunic carotenoids. Oxygenate volatile compounds were extracted by simultaneous distillation and extraction/concentration apparatus and analyzed by gas chromatography and mass spectrometery. Total 63 compounds were identified and some of them were caused by thermal degradation. They included 1,3,5-trimethylbenzene, 3,5,5-trimethyl-3-cyclohexen-1-ol, 3,5,5-trimethyl-3-cyclohexen-1-one, 1,1,2,3-tetramethyl-2-cyclohexen-5-ol, 1,1,2,3-tetramethyl-2-cyclohexen-5-one, 2,3,4,4-tetramethyl-6-hydroxy-2-cyclohexene-1-one, 1,2,3,8-tetrahydro-3,3,6-trimethyl-1-naphtol, dihydroacetinidolide, ${\beta}-ionone$, 2-(1,1,5-trimethyl-3-hydroxy-5-cyclohexen-6-yl)-1-tolylethene, 2,6-dimethyl-8-(1,1,5-trimethyl-3-hydroxy-5-cyclohexen-6-yl)-1,3,5-octatriene-7-yne. Proposed mechanism of formation of some compounds as thermal degradation products of ascidian tunic carotenoids are provided.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.304-310
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• 1986

A. calcoaceticus C10 grown on cyclohexanol as sole source of carbon and energy produced cyclohexanol dehydrogenase(CDH) and glucose dehydrogenase (GDH) concomitantly. CDH and GDH were different in coenzyme, induction and electrophoretic patterns. CDH depended for activity on $NAD^+$ only, while GDH required $NAD^+$ or $NADP^+$ alternatively. CDH was produced in the medium added cyclohexanol, but GDH was produced in various media such as LB, LB added 0.2% glucose or cyclohexanol and cyclohexanol medium. Productivity of CDH in A. calcoaceticus C10 was enhanced about 8 times by the addition of 0.2% cyclohexanol to LB medium after 4 hours as much as LB medium only. Production of CDH was induced by cyclohexanol, cyclohexanone, cyclohexan-1,2-diol and cyclohexene oxide, but not induced by ${\varepsilon}-caprolactone$ and adipate.

• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.670-677
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• 2010

A comparative study on the Au(I)-catalyzed and IBr-promoted tandem cyclization of 1,5-enyne was reported. This study provides a meaningful mechanistic insight to the concerted nature of this tandem reaction and also provides interesting applications in the synthesis of 7/5- or 8/5-fused bicycles and biaryls.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1819-1822
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• 2005

In the search for a simple preparation method of heterogeneous catalyst, the iron porphyrins were coordinated bonded to the surface of a polymeric core-shell nanosphere. The heterogeneous catalyst was characterized by FT-IR, scanning electron microscope, and UV-vis spectrophotometer. The iron porphyrin bound core-shell nanospheres was about 470 nm in diameter and their catalytic activity for cyclohexene oxidation was similar to a homogeneous iron porphyrin in a solvent composition range of 25-75% acetonitrile/water (v/v). In addition, they could be recovered by simple centrifugation and their catalytic activity was maintained more than the third cycle.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.503-506
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• 2010

• Journal of the Korean Applied Science and Technology
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• v.15 no.2
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• pp.41-48
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• 1998

The catalytic oxidations of several cycloolefins in $CH_2Cl_2$ were been investigated using Mn(III)-, Fe(III)-porphyrin complexes as a catalyst and sodium hypochlorite as a terminal oxidant. Porphyrins were $(p-CH_3O)TTP,\;(p-CH_3)TTP,$ TPP, (p-F)TPP, (p-Cl)TPP and $(F_{20})TPP$ (TPP = tetraphenylporphyrin), and olefins were cyclopentene, cyclohexene and cycloheptene. The substrate conversion yield was discussed according to the substituent effects of metalloporphyrin. The conversion yield of substrate by changing the substituent of TPP increased in the order of $p-CH_3O$ < $p-CH_3$ < H < p-F < p-Cl, which was consistent with the sequence of $4{\sigma}$ values of TPP. The conversion of cycloalkene followed the order of $C_5\;<\;C_6\;<\;C_7$.

• Journal of the Korean Applied Science and Technology
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• v.21 no.1
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• pp.76-88
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• 2004

The catalytic oxidation reaction of several cycloolefins in $CH_2Cl_2$ have been investigated using non-redox metalloporphyrin(M = Ga(III), In(III) and TI(III) complexes as a catalyst and sodium hypochlorite as a terminal oxidant. Porphyrins were $(p-CH_3O)$TPP, $(p-CH_3)$TPP, TPP, (p-F)TPP, (p-Cl)TPP and $(F_{20})$TPP (TPP=5,10,15,20-tetraphenyl-21H,23H-porphyrin) and olefins were cyclopentene, cyclohexene, cycloheptene and cyclooctene, The substrate conversion yield(%) was investigated according to the radius effect of non-redox metal ion, substituent effect and hindrance effect of metalloporphyrin. The conversion yield of cycloolefin was in the following order : $C_5$ < $C_6$ < $C_7$ = $C_8$.