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3-Phenyloxadiazole 유도체의 1,3-dipolar Cycloaddition 반응에 미치는 온도의 영향
황성규,이기창,최봉종,이광일 ( Sung Kwy Hwang,Ki Chang Lee,Bong Jong Choi,Kwang Ill Lee ) 한국유화학회 1997 한국응용과학기술학회지 Vol.14 No.3
Ultraviolet spectrophotometric investigation has been carried out on the rate constants for 1,3-dipolar cycloaddition of 4-substituted-3-phenyloxadiazole derivatives with dipolarophiles such as phenyl acetylene, propiolic acid methyl ester and dimethylacetylene dicarboxylate. From there, the rate constants for 1,3-dipolar cycloaddition were determined at 80, 100 and 120℃, and the reaction rates were increased with increasing temperature, From these rate constants, the values of the thermodynamic activation parameters were obtained. Some thermodynamic activation parameters such as E_a, △H^*, △S^* and △G^* from Arrhenius equation were also calculated for the electrophilic 1,3-dipolar cycloaddition of 3-phenyloxadiazole derivatives with dipolarophiles. In order to the proposal the mechanism and reactivity of 1,3-dipolar cycloadditioin reaction, the effect of substituents having various kinds of electron withdrawing or releasing groups were examinated. Considering the effect of substituents, an electron withdrawing group attached at the 4-carbon position in 3-phenyloxadiazole derivatives decreases the reaction rate because of the lack of electron density in 3-phenyloxadiazole ring.
이기창,양천회,최봉종 ( Ki Chang Lee,Chun Hoi Yang,Bong Jong Choi ) 한국유화학회 1985 한국응용과학기술학회지 Vol.2 No.2
AOM and lamp tests were carried out with soybean, corn, palm oil and beef tallow without the addition of antioxidant. The evaluation of rancidity for the stability was determined by changes of peroxide value and acid value, and the correlation between the stability and the composition of fats and oils was examined. The results obtained were as follows. 1. In the AOM test, POV began to rise in the order of corn oil, soybean oil, beef tallow and palm oil. However, the time required to reach POV 100 in beef tallow was faster than other fats and oils. It was found that there was a good correlation between POV and content of tocophrol. 2. In the lamp test by light of main wavelength 253.7nm, beef tallow was stabler than soybean and corn oil. It was because the absorption of light into beef tallow was much smaller than others, since beef tallow was fats. Palm oil was very stable in all the samples during AOM and lamp test.
Oadiazole 유도체의 고리화 첨가반응에 의한 Pyrazole 유도체의 합성
이기창,황성규,이광일,최봉종 ( Ki Chang Lee,Sung Kwy Hwang,Kwang Ill Lee,Bong Jong Choi ) 한국유화학회 1997 한국응용과학기술학회지 Vol.14 No.1
The synthetic method of pyrazole was performed by 1,3-dipolar cycloaddition with dipolarophileinstead of the reaction between diazomethane and acetylene. The cycloaddition mechanism and reac-tivity of 3-phenyloxadiazole derivatives with dipolarophiles was investigated. In order to investigatethe mechanism and reactivity of this cycloaddition, the effect of substituents having various kinds ofelectron withdrawing of releasing groups were examinated. Considering the effect of substituents, anelectron withdrawing group attached at the 4-carbon position in 3-phenyloxadiazole derivatives decrease the reaction rate because of the lack of electron density on oxadiazole ring. The reaction rate of3-phenyloxadiazole derivatives with dipolarophiles were more conveniently measured using UV thanusing a volumetric analysis which was used before. From the result of this study, it was that thecycloaddition was found to be a first-order reaction depending upon the concentration of 3-phenyloxadiazole only.
금속산화물 개시제에 의한 Methylmethacrylate의 라디칼중합
李基昌,崔鳳鍾 명지대학교 1983 明大論文集 Vol.14 No.-
Polymerization of methymethacrylate (MMA) with lead dioxide as a heterogeneous catalyst has been studied at 50℃ in benzene. The rate of polymerization was given by the reaction R_p∝[PbO_2]^(1/2)[MMA]^2. The apparent activation energy was 5.5 Kcal/mol. From the copolymerization of MMA with styrene and the effect of an initiator, it was found that the polimerization of MMA took place by a radical mechanism. PbO_2 initiated the polimerization of MMA and vinyl acetate but was completely in effective for St and acrylonitrile. Adding N.N'-dimethy aniline to the reaction system, the rate of polimerization of MMA was accelerated. It was concluded that the polymerization was initiated by dehydrogenation of MMA.
2-Furyl chalcone유도체에 대한 Thiourea의 친핵성 첨가반응 연구
최봉종,배광석,이기창 明知大學校 産業技術硏究所 1995 産業技術硏究所論文集 Vol.14 No.-
The addition reaction kinetics of, 2-furyl chalcone derivatives were investigated by ultraviolet spectrophotometery in 30% dioxane-H2O at 25℃ The structure of these compounds were ascertained by means of ultraviolet, melting point IR and NMR spectra. The final product was 2-furyl chalcone- β -thiourea synthesized by the addition of thiourea for the 2-thienyl chalcone. The rate equations which were applied over a wide pH range (pH 1.0∼ 13.0) were obtained. The substituent effects on 2- furyl chalcone derivatives were studied, and the addition reaction were facilitated by electron acting groups. On the basis of the rate equation and effect of substitutent general base, the plausible addition reaction mechanism was proposed Below pH 4.0 It was only proportional to concentration of hydronium ion, At pH 4.0∼9.0 neutral thiourea molecule or anion competitively attacked on the double bond. Above pH 10.0, It was proportional to concentration of hydroxide ion.
3-Phenylsydnone 유도체와 친쌍극체와의 Cycloaddition 반응메카니즘에 관한 연구
李基昌,崔鳳鍾 明知大學校 産業技術硏究所 1986 産業技術硏究所論文集 Vol.5 No.-
The cycloaddition reaction mechanism and reactivity of 3-phenylsydnone and its 4-substituted-3-phenylsydnones with dipolarophiles was more conveniently investigated by measuring the reaction rates with UV spectrophotometry. An electron withdrawing group attached at the 4-carbon position in 3-phenylsydnone and its derivatives decrease the reaction rate because of the lack of electron density in sydnone ring. From the result of this Kinetic study, it was known that the cycloaddition reaction was found to be a first-order reaction depending upon the concentration of 3-phenylsydnone only. The synthetic method of pyrazole was performed by 1,3-dipolar cycloaddition reaction with dipolarophile instead of the reaction between diazomethane and acetylene which was used before.
음이온성 아크릴아미드와 아크릴산의 역유화 중합에 관한 연구
최희천,이기창,최봉종,이광일 한국유화학회 1989 한국응용과학기술학회지 Vol.6 No.1
To developed new process for obtaining maximum molecular weight of anionic acrylamide and acrylic acid copolymer by lnverse emulsion polymerization. Concentration of initiator, reducing agent, surfactant and mole ratio of acrylamide-acrylic acid were studied for the process. Semi-batch processes with method of redox, control of reaction temperature, feeding method of monomer and reaction time, was suitable for maximum molecular weight of P(AMAC) from this process obtained 3.09 × 10exp(6)(M ̄n.) and 4.41 × 10exp(6)(M ̄w.) in molecular weight measured by the intrinsic viscosity method. lnverse emulsion polymerization mechanism of P(AMAC) does not followed the Smith-Ewart and Medvedv theory, but selected for concentration of initiator, reducing agent, surfactant, water solubility of monomer.