• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3914-3922
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• 2011

3-Chloro-1-benzothiophene-2-carbonyl chloride 1 was reacted with glycine in acetone to give 3-chloro-1-benzothiophen-2-yl-carbonylaminoacetic acid 2. Various aldehydes on treatment with compound 2 in acetic anhydride to gave 1,3-oxazol-5-ones 3a-d. These oxazolones was treated with aromatic amines or hydrazides to get various imidazol-4-ones 4a-t or 5a-l. Oxazolones 3a-d was also treated with aromatic hydrazines, expansion of five member oxazole ring to six member triazine ring occurs to yield 1,2,4-triazin-6-ones 6a-h. The structures of all the synthesized compounds were confirmed by spectral data and had been screened for antibacterial activity.

• 대한화학회지
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• 제55권5호
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• pp.794-804
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• 2011

3-Chloro-1-benzothiophene-2-carbonylchloride (1) was allowed to react with glycine to give 3-chloro-1-benzothiophen-2-yl-carbonylaminoacetic acid (2). Various aldehydes were treated with compound (2) in acetic anhydride to get 1,3-oxazol-5-ones (3a-d). These oxazolones were treated with aromatic amines or hydrazides to get various imidazol-4-ones (4a-h or 5al) separately. Oxazolones was also treated with aromatic hydrazine, through which expansion of five membered oxazole ring to six member triazine ring occurs to yield 1,2,4-triazin-6-ones (6a-h). The structures of all the synthesized compounds were confirmed by spectral data and were screened for antibacterial and antifungal activities.

• 펄프종이기술
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• 제36권1호
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• pp.61-66
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• 2004

Bleached chemithermomechanical pulp (BCTMP) was produced from CTMP of Betula maximowicziana Regel by two staged ozone-hydrogen peroxide bleaching in order to improve the optical properties of high yield pulp. This pulp was used for the evaluation of optical properties improvement, chemical characteristics of lignin in fiber and the relationship between lignin and optical properties in fiber cell wall. Hydrogen peroxide treatment improved the brightness, but the post color number (PC No.). There was little improvement on optical properties by ozone treatment, but this could be improved more by using two staged ozone-hydrogen peroxide bleaching. The hydrogen peroxide treatment did not make any change on chemical characteristics of lignin in cell wall, but by ozone treatment, it was found that the non-aromatic conjugated structure was existed in the surface of cell wall, but this could be removed by hydrogen peroxide treatment in two staged ozone-hydrogen peroxide treatment. Therefore, the optical properties was significantly improved, due to the removal of non-aromatic conjugated structure.

• Journal of the Korean Wood Science and Technology
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• 제18권4호
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• pp.79-85
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• 1990

Many kinds of acetosolv lignin including ricestraw and spruce lignin were pyrolyzed. and liquefied in the autoclave reactor using 50% tetralin and m-cresol solution respectively as soluble solvent and Co-Mo as catalyst. In order to promote deoxyhydrogenolysis reaction $H_2$ gas was supplied into the reactor. The ratio between lignin and the soluble solvent are lg and 10cc. The reaction conditions are $200^{\circ}-700^{\circ}C$ of reaction temperature, 10-50 atms of reaction pressure and 100-500rpm of the reactor stirrer. By the deoxyhydrogenolysis liquefaction reaction, the main chemical structures of lignin which are aryl-alkyl-${\beta}$-0-4 ether, phenylcoumaran and biphenyl etc. are easily destroyed into liqufied aromatic compounds and aliphatic compunds linked with aromatic compounds. The percent yield of monomeric phenols on the weight bvase of lignin reacted reached to 12-14% by the chemical analytic GC-MS etc.

• 대한화학회지
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• 제9권2호
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• pp.78-80
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• 1965

The organic yields(i.e., fraction of nuclear events resulting in organic compound formation) of the radioactive neutron capture reactions of the halogens in purified aromatic halides have been determined in the liquid and solid state, in the presence of scavenger, elemental halogen for thermal atoms, and in the presence of oxygen. Among the important results are; (1) organic yields of the halides are due in part to hot processes and in part to thermal processes; (2) temperature (from liquid state to solid state); (3) the organic yield of chlorobenzene is the same in the solid phase as in the liquid phase whereas the yields of the bromo-and iodobenzene are higher in the solid.

• 대한화학회지
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• 제55권4호
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• pp.662-665
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• 2011

실온에서 방향족 알데히드, 말론니트릴과4-히드록시쿠마린을neat 실리카젤 속에서 one-pot반응시켜서 3,4-dihydropyrano[c]chromenes을 좋은 수율로 합성하였다.

• Elastomers and Composites
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• 제55권3호
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• pp.205-214
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• 2020

A series of wholly aromatic polyhyroxyamide (PHA) copolymers were prepared by direct polycondensation reaction of isophthalic acid and diacids containing bulky units with 3,3'-dihydroxybenzidine. The inherent viscosities of the PHAs measured at 35℃ in DMAc solution were in the range of 0.31-0.56 dL/g. The solubility study revealed that the PHAs were readily soluble in aprotic solvents such as, dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), and N-methyl-2-pyrrolidone (NMP) at room temperature and in less polar solvent such as pyridine. However, the polybenzoxazole (PBO) copoymers were quite insoluble in all organic solvents except partially soluble in concentrated sulfuric acid and partially soluble in NMP containing LiCl. The PBO copolymers showed maximum weight loss temperature in the range of 593-632℃ and high char yields in the range of 65.0-71.2% at 900℃ in a nitrogen atmosphere.

• 한국약용작물학회지
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• 제10권2호
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• pp.126-131
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• 2002

황칠수액 분비량을 개체 및 서식지별 차이가 있는지를 검토하고, 차이가 있다면 이를 토대로 서식환경 및 우수개체선발을 위한 기초자료를 수집하고자 하였다. 황칠수액 분비량을 기준으로 우수개체를 선발하고 선발 개체군을 중심으로 주요 방향성 정유성분의 동정 및 분포 양상을 조사하였다. 황칠나무 수액은 서식지별, 수령 및 개체별 차이가 확인되었으며, 분비량을 기준으로 우수개체를 선발하였다. 선발된 개체에서의 주요 정유성분에서${\beta}-elemene,\;germacrene-D,\;{\beta}-selinene,\;{\alpha}-selinene,\;{\gamma}-cardinene,\;{\delta}-cadinene$ 등이 었으며, 그 중에서도 germacrene D가 주요 구성성분임이 확인되었다. 선발개체의 주요 정유성분의 구성비율은 서식지별 및 각 개체별 차이가 존재하였다.

• 한국환경과학회지
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• 제11권4호
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• pp.375-382
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• 2002

The total hydrocarbon distribution of oil products obtained from the pyrolysis of four kinds of mixtures of polyethylene-polystyrene waste has been studied by multidimensional chromatography(high performance liquid chromatography followed by capillary gas chromatography)/mass spectrometry. Saturated, unsaturated and aromatic hydrocarbons in oil products were selectively pre-separated according to structural groups by HPLC and the weight fraction of each group was estimated by analysis of each component using GC-FID response factors. The hydrocarbon distribution of aliphatic fraction consists of $C_{5}$ to $C_{25}$ saturated and unsaturated hydrocarbons. And that of aromatics fraction consists of benzene, toluene, xylene, styrene, propenyl benzene, naphthalene, and some of derivatives. Pyrolysis temperature did not affect the ratio of total weight fraction of aliphatic over aromatic hydrocarbon distribution in case of PS only and PE-PS mixtures (1:1 and 1:4 wt. ratio) as a feed while affected the ratio of total wt. fraction in case of PE only. The optimal temperature for the maximum oil production was $600^{\circ}C$ for pyrolysis of PS and 1:1 and 1:4 mixtures of PE and PS. The optimal condition for aromatic recovery was $600^{\circ}C$ with 1:1 mixture of PE and PS. In this condition, aromatic was produced up to 90% of total oil product. The maximum yield of toluene, xylene, styrene, and propenyl benzene were 8.6, 8.9, 51.0 and 7.4% of feed for pyrolysis PS at $700^{\circ}C$, respectively. However, only 1.3% naphthalene was recovered at $700^{\circ}C$ with 1:1 PE:PS(by wt.).

• 대한화학회지
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• 제55권4호
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• pp.644-649
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• 2011

Polyaniline/$SiO_2$ 촉매를 이용하여, acetophenone, aromatic aldehydes와 aromatic amines을 에탄올 용매 속에서 반응시켜서 다양한 various ${\beta}$-amino ketones을 one-pot mannich 반응을 수행하였으며, 이 반응을 위해 silica가 충진된 여러 가지 종류의 wt% polyaniline을 화학적인 산화방법에 의해 합성하였다. 합성한 촉매는 thermal analysis(TG-DTA), X-ray diffraction (XRD), scanning electron microscopy(SEM) energy dispersive spectroscopy(EDS), 및 Fourier transform infrared spectroscopy (FT-IR) 방법으로 확인하였으며, 촉매의 용매에 대한 안정도 UV-Visible spectroscopy로 측정하였다. Polyaniline/$SiO_2$ 촉매를 이용하는 합성 방법은높은 수율로 얻어지며, work up이 쉽고, 독성이 없으며, 쉽게 회수하여 재사용이 가능하다.