• Bulletin of the Korean Chemical Society
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• v.7 no.1
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• pp.42-45
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• 1986

Quenching of excimer fluorescence from polystyrene-acrylic acid copolymers containing $Eu^{3+}$ has been studied in tetrahydrofuran solution using simple aromatic hydrocarbons as quenchers under steady-state conditions. Aromatic hydrocarbons quenched collisionally the excimer fluorescence and their rate constants of quenching were determined. The magnitude of quenching constant is interpreted in terms of the cube root of the molar volume of quencher. Cycloalkanes were not effective in quenching the excimer fluorescence possibly due to different solubility characteristics from aromatic hydrocarbons.

• Bulletin of the Korean Chemical Society
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• v.13 no.6
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• pp.654-658
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• 1992

Photolysis of 1-phenyl-1,3,5-hexatriynes in deaerated tetrahydrofuran gave photoreduction and photoaddition products, while photolysis of 1-phenyl-1,3,5-hexatriynes in deaerated alcoholic solvents (methanol, i-propanol) yielded dark red products, probably oligomers or decomposition products of reactants, as exclusive major products. A plausible mechanism for the reaction is proposed.

• Bulletin of the Korean Chemical Society
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• v.6 no.3
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• pp.164-168
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• 1985

The fluorescence emission of polystyrene-acrylic acid copolymers containing $Eu^{3+}$ in tetrahydrofuran solution was investigated by spectrofluorimetry. The excimer emission increased linearly with the polymer concentration up to approximately $5{\times}10^{-3}$M. Benzene and toluene collisionally quenched the excimer fluorescence and thier rate constants of quenching were determined. Quenching efficiencies decreased in the order: naphthalene > toluene > benzene. Analyses of Rayleigh scattering and europium emission showed no measurable structural changes observed under the experimental conditions.

• Journal of the Korean Institute of Gas
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• v.18 no.6
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• pp.1-6
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• 2014

This study is based on a investigation regarding the evaporation rate of a volatile liquid(methanol, tetrahydrofuran, xylene) according to changes of the temperature and wind. The weight of a volatile liquid was standardized to 24 g and the mixture was formed with the same weight ratio. In order to discover about the effect of the wind velocity, small fan was installed at 10 cm above the entrance and 30 cm away in the direction of the cylinder. The effect of the wind velocity was tested at 0 m/s, 1.63 m/s, 2.03 m/s respectively and the effect of the temperature on the volatile liquid was experimented at the temperature of $21^{\circ}C$, $32^{\circ}C$, $52^{\circ}C$ in the constant temperature water base. As a result, in case of Xylene, the evaporation rate of the tetrahydrofuran and methanol showed 1.4 mg/min, 19.8 mg/min and 10.2 mg/min respectively. Also, the effect of the evaporation rate on the temperature of the volatile liquid and on the velocity of wind was shown to be very sensitive. At the same time, the evaporation rate of the mixture showed large difference compared to that of the single volatile liquid.

• Analytical Science and Technology
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• v.6 no.4
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• pp.383-390
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• 1993

Retention behaviors of aliphatic and aromatic compounds were investigated with Van der Waals volume which represented the molecular size. The organic solvents, methanol, acetonitrile and tetrahydrofuran, were mixed with water at various ratio, respectively. The selectivity of organic solvents were tested by change of column temperature. The capacity factor was increased linearly according to the enlargement of molecular size. Therefore, Van der Waals volume was useful to predict the elution of organic molecules in reversed-phase column. The order of elution capacity of solvents was methanol

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.1018-1022
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• 1998

Characteristics and catalytic activities of 12-molybdophosphoricacid catalysts modified by ring opening polymerization of tetrahydrofuran (THF) were studied in this work. 12-Molybdophosphoricacid catalysts modified by THF showed higher conversions and product yields than the mother acid in the vapor-phase ethanol conversion. It was believed that the enhanced catalytic activities of modified 12-molybdophosphoricacids were due to structural flexibility of heteropolyanions and weakened hydrogen bond around heteropolyanions. THF interacted with protons and crystalline water molecules of heteropolyacids. The interaction between THF and heteropolyanoins, which crystalline water molecules act as intermediary, was the dominant factor deciding the catalytic activities of modified 12-molybophosphoricacids.

• Reproductive and Developmental Biology
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• v.34 no.1
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• pp.7-13
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• 2010

The binding affinity constants ($p(Od)_{50}$) and molecular docking scores (OS) between porcine odorant binding proteins pOBP (1HQP) and pPBP (1GM6) as receptor and a series of tetrahydrofuran-2-yl (A & B) analogues as substrate, and their interactions were discussed quantitatively using three-dimensional quantitative structure-activity relationship (30-QSAR) models. The statistical qualities of the optimized CoMF A models for pOBP were better than those of the CoMSIA models. The binding affinity constants and OS between substrate and receptor molecules were dependent upon steric and hydrophobic interaction. The DS constants of the substrates into the binding site of OBP (1HQP) were bigger than those of PBP (1GM6). The resulting contour maps produced by the optimized CoMFA model were used to identify the structural features relevant to the binding affinity in binding site of pOBP.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.221-226
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• 2008

Novel synthetic routes were proposed for hydroxy-terminated Poly(EO-co-THF) by Cationic ring-opening copolymerization of Tetrahydrofuran(THF) and Ethylene oxide(EO). It was carried out using Boron trfluoride tetrahydrofuranate($BF_3$ THF complex) as catalyst in the presence of 1,4-butandiol. The resultant products are well-defined linear polyetherpolyol. Polyurethane(TPU) were prepared using resultant polyetherpolyol with IPDI/N-100 as curing agent and TPB(Triphenylbismuth) /MA(Maleic anhydride) mixture as cure catalyst. Mechanical properties of TPU prepared from poly(EO-co-THF) polyol were investigated and compared with polyurethane using ATK HTPE.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.100-106
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• 1992

The fluorescence characteristics of copolymers of styrene-maleic anhydride(PSMAn), styrene-maleic acid (PSMA), and PSMA complexed with $Eu^{3+}$ (PSMA-Eu) in tetrahydrofuran were studied. The excimer of PSMA and PSMA-Eu with 75% mole fraction of styrene appears to have larger binding energy than that with 50% or 67% styrene. The ratio of excimer to monomer intensities showed little change with the increase of styrene concentration up to $8.0{\times}10^{-3}M$, indicating the excimer formation is due to intramolecular process. Three existing mechanisms for intramolecular excimer formation are considered inadequate to explain the observed behavior. The quenching of excimer intensity by benzyl-acetate, mesitylene, and $CCl_4$ is interpreted in terms of the molar volume of quencher.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.231-236
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• 2008

The well-defined copolymers derived from Epichlorohydrin(ECH), Tetrahydrofuran(THF) were synthesized by Cationic ring-opening polymerization(CROP) with 1,4-Butandiol, a initiator, and $BF_3THF$ Complex, a catalyst via Activated monomer mechanism, which could lead to hydroxyl-terminated polyethers. The molecular weight of polymers were dependant on the ratio of [monomer]/[diol], Copolymer structures were controlled by monomers feed ratio, ECH and THF added. This polymers were functionalized from Chlorine group to Azide group using $S_N2$ reaction. Synthesized polymers were found to be as the prepolymer for polyurethane. Polyurethane was synthesized in the presence of N-100/IPDI mixture, a curing agent, and TPB(triphenyl bismuth)/MA(Maleic anhydride) mixture, a catalyst system. The curing behavior and mechanical properties of polyurethane after mixing with various prepolymer’s composition and the molecular weight were studied.