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

• Journal of Microbiology and Biotechnology
• /
• 제10권4호
• /
• pp.518-521
• /
• 2000

Aspergillus niger is capable of metabolizing dimethyphthalate. The maximum weight of mycelium wa observed afterabout 6-8 dys of incubation. A TLC analysis revealed the accumulation of metabolites in the resting cell culture. Monomethylphthalate, phthalate, and protocatechuate were shown to be the intermediates by thin layer chromatographic and spectrophotometric analyses. The fungus metabolized dimethylphthalate through monomethylphthalate, phthalate, and protocatechuate as evidenced by the oxygen uptake and an enzymatic analysis. The terminal aromatic metabolite, protocatechuate, is metabolized via the ortho-cleavage pathway.

• 한국응용과학기술학회지
• /
• 제2권2호
• /
• pp.25-30
• /
• 1985

The transesterification reaction between diethanolamine and dimethylphthalate was kinetically investigated in the presence of various metal acetate catalysts at $130^{\circ}C$. The reaction was followed by the measurement of distilled methanol from the reaction vessel. The transesterification was found to obey first-order kinetics with respect to the concentration of diethanolamine and dimethylphthalate and catalyst, respectively. The reactivities has highest value where the electronegativity and instability constand (Kij) values for the metal acetate catalysts are about 1.6.

• 한국응용과학기술학회지
• /
• 제9권2호
• /
• pp.141-148
• /
• 1992

Transesterification reactions (methyl methacrylate with diethanolamine, ethylene glycol with dimethylphthalate) were kinetically investigated in the presence of zinc compound catalysts at $120{\sim}170^{\circ}C$ The amount of reactants was measured by gas chromatography. and the reaction rates also measured from the amount of reaction products and reactants upon each catalyst. The transesterification reactions were carried out under the first order conditions respect to the concentration of reactants, respectively, The overall reaction order was 2nd. The apparent rate constant (k') was found to obey first kinetics with respect to the concentration of catalyst. It shows that according to an increase in basicity of anionic species the rate constant increase, and that a linear relationship exists between ln k and pKa in transesterification reaction of methyl methacrylate with diethanolamine.

• 한국응용과학기술학회지
• /
• 제7권1호
• /
• pp.71-76
• /
• 1990

Transesterification reactions (methyl methacrylate with monoethanolamine, methyl methacrylate with n-butyl alcohol, dimethylphthalate with ethylene glycol, dimethyl phthalate with monoethanolamine) were kinetically investigated in the presense of various metal acetate catalysts at $110^{\circ}C$. The amount of reactants was measured by gas and liquid chromatography, and the reaction rates also measured from the amount of reaction products and reactants upon each catalyst. The transesterification reactions were carried out under the first order conditions respect to the concentration of reactants, respectively. The overall reaction order was 2nd, Maximum reaction rates were appeared at the range of 1.4 to 1.6 in electronegativity of metal ions and maximum catalytic activities were obserbed at the range of 1.5 to 1,8 in instability constant of metal acetates.

• 한국의류산업학회지
• /
• 제11권4호
• /
• pp.672-677
• /
• 2009

To reduce the dependence of wool dyeing on the temperature several solvents with different properties and structures were added to the dye bath of C. I. Acid Yellow 42. Nearly the same total solubility parameters(${\delta}_t$) of solvents as those of wool fiber and hydrophobic part of the dyestuff were needed to increase disaggregation of dye molecules, loosening the wool fiber and wickabilty of dyeing solution; besides, the large surface tension(${\gamma}$) value of the solvents and the well balanced values of the three-component Hansen solubility parameters such as dispersion(${\delta}_d$), polar(${\delta}_p$), and hydrogen(${\delta}_h$) bonding parameters were required. Among the added solvents dimethyl phthalate(DMP) and acetophenone(AP) were satisfied with these conditions and worked the most successfully in the low temperature wool dyeing. Their effectiveness proven by the dyeing rate and the activation energy ($E_a$) of the dyeing was in the order of DMP > AP > DBE > CH > M >NONE. In conclusion the total solubility parameters(${\delta}_t$), the three-component Hansen parameters and the surface tension(${\gamma}$) of DMP and AP could be the guidelines to select suitable solvents for low temperature wool dyeing.

• 분석과학
• /
• 제13권5호
• /
• pp.683-692
• /
• 2000

음식포장용 필름은 열이 노출시 재질과 첨가제들에 기인한 휘발성 화합물들이 방출된다. 그러나 이러한 휘발성 유기화합물은 기존의 용매추출법을 이용한 시험방법으로는 평가하기가 어렵다. 따라서 본 연구에서는 실생활에서 사용되고 있는 식품용 플라스틱 필름의 사용조건을 고려해줄 수 있는 열추출장치를 개발하였다. 그리고 PVC재질의 식품용 필름을 실생활에서 사용하는 온도범위($50-120^{\circ}C$)에서 열노출시켜 발생하는 휘발성 유기화합물들을 on-column 저온농축방법을 사용하여 GC/MS로 분석하였다. PVC필름을 열노출 시켰을 때 방출되는 휘발성 유기화합물을 분석한 결과, $C_{12}-C_{18}$의 파라핀계 탄화수소류와 내분비계 교란물질로 알려진 터트부틸페놀과 디메틸프탈레이트와 노닐페놀을 포함한 알킬페놀류가 확인되었다. 테트라메틸부틸페놀은 $50^{\circ}C$에서는 $0.07ng/cm^2$였고, 온도에 따라 증가하여 $100^{\circ}C$에서 $3.94ng/cm^2$의 가장 높은 방출량을 나타냈다.