• 대한화학회지
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• 제21권4호
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• pp.270-275
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• 1977

Modulated light signal과 trimethylsilyl 유리기의 전자상자성 공명 signal과의 phase shift를 측정함으로써 t-butoxy 유리기와 trimethylsilane의 절대 반응속도 상수는 $-50^{\circ}C$에서 $3{\times}10^{-2}M^{-1}{\cdot}sec^{-1}$으로 얻을 수 있었다.

• Elastomers and Composites
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• 제28권3호
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• pp.183-190
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• 1993

The radical copolymerization with propagation and depropagation is presented in order to estimate reactivity rate of monomers and $K_{11}$(the equilibrium constant for propagation and depropagation) in the copolymerization of ${\alpha}-methylstyrene-co-methylmethacrylate$ and ${\alpha}-methylstyrene-acrylonitrile$. The value of ${\alpha}-methylstyrene$ and methylmethacrylate and $K_{11}$ are found to be 0.48, 0.47 and 5.0 respectively. The value of ${\alpha}-methylstyrene$ and acrylonitrile and the $K_{11}$ are found to be 0.1251, 0.0577 and 23.8 respectively. The treatment rate constant of ${\alpha}-methylstyrene-co-methylmethacrylate$ and ${\alpha}-methylstyrene-co-acrylonitrile$ in the copolymerization is estimated to be 2.5, 80.72 regardless of monomer feed composition.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2002년도 정기총회 및 제9회 광과학 학술심포지움 논문초록
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• pp.66-66
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• 2002

• 한국대기환경학회지
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• 제17권5호
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• pp.407-414
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• 2001

In this study, the absorption kinetics of $CO_2$onto a mixture of AMP (2-amino-2-methyl-1-propanol) MEA (monoethanolamine) water were investigated at 30 and 4$0^{\circ}C$ using a packed absorption tower. Solubility and absorption rate of $CO_2$into alkanolamine solutions and optimal condition of $CO_2$absorption process were investigated. The experimental conditions are as follows; temperature of 30 and 4$0^{\circ}C$, gas flow rate of 3ι/min for the absorption tower, and liquid flow rate of 0.1ι/min. Feed gas was a mixture of 85% $N_2$and 15% $CO_2$. The experimental results showed that AMP had greater solubilities and faster absorption rates than MEA and DEA. In addition, MEA had the fastest initial reaction rate. To improve the properties of AMP which have low initial reaction rate and high cost, AMP was used with MEA. The mixing ratio was also changed in constant total molarity of 1,2,3 and 4. The experimental results can be summarized as follows: (1) in solubility experiment, the addition of MEA in constant total polarity decreased the solubility of $CO_2$in AMP/MEA mixture. (2) from 0 to about 0.3 in mixing ratio, the solubility of $CO_2$in AMP/MEA mixture had little differences compared with the sum of solubility of AMP only and solubility of MEA only . (3) mixing ratio of 0.3 was found to be an optimal point with the fastest $CO_2$absorption rate.

• 공업화학
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• 제28권5호
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• pp.597-600
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• 2017

4,4'-비피리딘과 크롬(VI) 산화물을 반응시켜 $(C_{10}H_8N_2H)_2Cr_2O_7$을 합성하였다. 적외선분광광도법(FT-IR)과 원소분석으로 구조를 확인하였다. 여러 가지 용매 하에서 $(C_{10}H_8N_2H)_2Cr_2O_7$을 이용하여 벤질알코올의 산화반응을 측정한 결과, 용매의 유전상수 값이 증가함에 따라 반응수율이 증가했다. 그 순서는 DMF (N,N'-디메틸포름아미드) > 아세톤 > 클로로포름 > 시클로헥센이었다. $H_2SO_4$ 촉매를 이용한 DMF 용매 하에서, $(C_{10}-H_8N_2H)_2Cr_2O_7$은 벤질알코올(H)과 그의 유도체들($p-OCH_3$, $m-CH_3$, $m-OCH_3$, m-Cl, $m-NO_2$)을 효과적으로 산화시켰다. 전자받개 그룹들은 반응속도가 감소한 반면에 전자주개 치환체들은 반응속도를 증가시켰고, Hammett 반응상수(${\rho}$) 값은 -0.70 (308 K)이었다. 본 실험에서 알코올의 산화반응 과정은 속도결정단계에서 수소화 전이가 일어났다.

• Bulletin of the Korean Chemical Society
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• 제31권8호
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• pp.2357-2360
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• 2010

Kinetic studies on the pyridinolysis of aryl dithiocyclopentanecarboxyaltes 2 were carried out at $60.0^{\circ}C$ in acetonitrile. In the aminolysis of 2, the $\beta_X$ values were 0.5 - 0.8 with anilines, and there was no breakpoint. However, in the pyridinolysis of 2, biphasic Bronsted plots were obtained, with a change in slope from a large value ($\beta_X{\cong}0.7$) to a small value ($\beta_X{\cong}0.4$) at $pK_{a}^0$ = 5.2. This was attributed to a change in the rate-limiting step from breakdown to the formation of a zwitterionic tetrahedral intermediate, $T^{\pm}$, in the reaction path, with an increase in the basicity of the pyridine nucleophile. An obvious change in the cross-interaction constant ${\rho}_{XZ}$ from a large positive ($\rho_{XZ}$ = +1.02) value to a small negative value (${\rho}_{XZ}$ = -0.17) supports the proposed mechanistic change.

• 에너지공학
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• 제14권2호
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• pp.105-111
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• 2005

본 연구는 마이크로 채널 반응기를 이용하여 다양한 실험조건에서 D-glucose용액을 이용하여 광촉매 분해특성을 연구하였다. Titanium oxysulfate의 수산화반응을 통하여 합성한 $TiO_2$수용액을 이용하여 마이크로 채널 반응기에 $TiO_2$를 코팅하였다. D-glucose광촉매 분해특성은 반응기의 주입유속이 증가함에 따라 증가하는 것으로 나타났으며 반응속도 상수와 Langmuir 흡수 제수를 다양한 실험조건에서 계산하였다. 또한 반응 시스템에서의 광효율을 계산하였다 따라서 이 연구는 배치 시스템에 적용된 $TiO_2$코팅이 되어 있는 마이크로 채널 반응기의 광분해 특성을 이해하기 위한 것이다.

• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3539-3543
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• 2012

Butacaine sulfate is an ester of p-aminobenzoic acid which has been widely used as a local anaesthetic and it is a long standing agent particularly for spinal anaesthesia. For this reason, a kinetic study of oxidation of butacaine sulfate by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB) has been carried out in $HClO_4$ medium at 303 K in order to explore this redox system mechanistic chemistry. The rate shows a first-order dependence on both $[CAB]_o$, and $[substrate]_o$, and a fractional-order dependence on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increases the rate of the reaction. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction has been found to be 1:2 and the oxidation products have been identified by spectral analysis. The observed results have been explained by plausible mechanism and the related rate law has been deduced.

• 한국응용과학기술학회지
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• 제9권1호
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• pp.41-46
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• 1992

The transesterification of dimethylphthalate by 1,4-butanediol was kinetically investigated In the presence of various metal acetate catalysts at 180$^{\circ}C$. The quantity of dimethylphthalate reacted in the reaction flask was measured by gas chromatography. The transesterification was assumed to obey first-order kinetics with respect to dimethylphthalate and 1,4-butanediol, and a rate equation was derived. The linear relationship was shown between apparent rate constant and reciprocal absolute temperature, the activation energy has been calculated as 7.4kcal with lead acetate. The maximum reaction rate was appeared at the range of 1.5${\sim}$1.6 of electronegativity of metal ions.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.123-127
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• 2005

EVA Powder modified high strength concretes were prepared by varying polymer/binder mass ratio with a constant water/binder mass ratio of 0.3. The effect of EVA powder on the slump, hydration heat, compressive and flexural strength, toughness and water absorption ratio was studied. In hydration heat test, temperature of hydration reaction displayed almost fixed level regardless of containing rate of EVA powder, but peak time of hydration reaction displayed late inclination as containing rate of powder increases. With the same water/binder mass ratio, the compressive strength and water absorption of EVA powder modified concretes decreased slightly when EVA powder was added and the flexural strength of EVA powder modified concretes rised slightly when EVA powder was added. Also, the toughness of the modified concretes can be improved markedly. The interpenetrating structure between the polymeric phase and cement hydrates formed at a $2{\sim}6%$(containing rate of EVA powder). The properties of the polymer modified concretes were influenced by the polymer film, cement hydrates and the combined structure between the organic and inorganic phases.