• 공업화학
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• 제9권4호
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• pp.591-594
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• 1998

Poly(caprolactone diol)을 기초로하여 합성한 microgel을 이용하여 bovine serum albumine (BSA)를 담지한 생분해성 microsphere를 용매증발법으로 제조하였다. 교반속도, microgel의 농도, 폴리비닐알콜의 농도등이 microsphere의 입도분포에 주는 영향을 조사하였다. Microsphere의 크기는 교반속도가 증가함에 따라 감소하였으나, 염화메틸렌 내의 microgel의 농도가 증가함에 따라서는 거의 비례적으로 증가하는 경향을 나타내었다. 100 unit/mL의 효소용액에서 microsphere의 생분해성에 관하여 조사한 결과, 3시간이 경과한 후에 microsphere의 표면에 작은 세공들이 나타나기 시작하였으며, 24시간 후에는 세공이 발달하고 크랙이 발생하기 시작하였다. 그리고 36시간 경과한 후에는 microsphere의 구형이 일그러짐을 관찰할 수 있었다.

• 접착 및 계면
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• 제18권4호
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• pp.179-182
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• 2017

본 연구에서는 polycaprolactone diol, castor oil과 4,4'-methylene dicyclohexyl diisocyanate 를 소프트 도메인으로, dimethylol butanoic acid를 내부 유화제로, trimethylamine을 중화제로 사용하여 다른 분자량을 가지는 prepolymer를 기초로 castor oil 기반의 수분산 폴리우레탄을 성공적으로 합성하였다. 분자량 변화에 따른 기계적인 물성 변화(UTM), 표면의 친수성 확인(contact angle), castor oil 유무에 따른 표면개질 변화(FE-SEM) 등을 평가 분석하였다. Castor oil 기반의 수분산 폴리우레탄의 경우 표면 친수성 향상 및 개질 변화를 기대할 수 있으며, 다양한 접착제 분야에 적용될 유망한 후보 물질로 여겨질 수 있을 것으로 예상된다.

• Macromolecular Research
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• 제13권1호
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• pp.73-79
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• 2005

Poly(L-lactic acid-co-succinic acid-co-l,4-butane diol) (PLASB) was synthesized by direct condensation copolymerization of L-lactic acid (LA), succinic acid (SA), and 1,4-butanediol (BD) in the bulk using titanium(IV) butoxide as a catalyst. The weight-average molecular weight ofPLASB was $2.1{\times}10^{5}$ when the contents of SA and BD were each 0.5 mol/100 mol of LA. Electrospinning was used to fabricate porous membranes from this newly synthesized bioabsorbable PLASB dissolved in mixed solvents of methylene chloride and dimethylformamide. Scanning electron microscopy (SEM) images indicated that the fiber diameters and nanostructured morphologies of the electrospun membranes depended on the processing parameters, such as the solvent ratioand the polymer concentration. By adjusting both the solvent mixture ratio and the polymer concentration, we could fabricate uniform nanofiber non-woven membranes. Cell proliferation on the electrospun porous PLASB membranes was evaluated using mouse fibroblast cells; we compare these results with those of the cell responses on bulk PLASB films.

• 한국연초학회지
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• 제31권2호
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• pp.85-94
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• 2009

This work has been conducted to develop a method for the analysis of neutral volatile flavors and their precursors in tobacco. The neutral volatile compounds and precursors in tobaccos have been investigated by Neutral Volatile scan method(NV scan) using Soxhlet extractor. The method has been used to analyze a range of different tobaccos and tobacco products. Neutral flavor compounds were classified as three sections(1st Volatile Fraction, Breakdown Flavor Products and Cembranoid Precursors). The major components of the First Volatile Fraction were 2-cyclohexene-1-one, 6-methyl-5-hepten-2-one, limonene and phenyl ethanol. The major components of Breakdown Flavor Products were isophorone, solanone, damascenone, 3-hydroxy-$\beta$-damascone, geranyl acetone, $\beta$-ionone, dihydroactinidiolide, norsolanadione, neophytadiene, hexahydrofarnesylacetone, farnesyl acetone and megastigmatrienone. The major cembranoid precursor compounds were dibutyl phthalate, duvatrenediols, 8,12-epoxy-14-labden-13-ol, 11-hydroperoxy-2,7,12(20)-cembratriene-4,6-diol, 12,15-epoxy-12,14-labadien-8-ol, 2,7,11-cembratrien-4,6-diol and 8,13-epoxy-14-labdien-12-ol. The NV scna results of tobacco types(flue-cured, burley and oriental) showed that each tobacco type has a characteristic flavor component profile.

• Korean Chemical Engineering Research
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• 제49권4호
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• pp.411-416
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• 2011

Isophorone diisocyanate(IPDI), polycarbonate diol(PCD), dimethylol propionic acid(DMPA)를 출발물질로 하여 NCO terminated prepolymer가 합성되었다. 이 prepolymer의 NCO기를 아크릴 단량체로 capping하기 위해 0~0.024 mole로 첨가량이 조절된 pentaerythritol triacrylate (PETA)가 첨가되었다. 제조된 acrylic terminated polyurethane 용액의 평균입경은 PETA의 첨가량이 증가함에 따라 증가하였다. 또한 제조된 코팅 필름의 연필경도 및 내마모성은 순수한 수분산 폴리우레탄보다 우수하였다.

• Bulletin of the Korean Chemical Society
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• 제28권2호
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• pp.229-234
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• 2007

One new compound, 3,7,11,19,23,27-hexamethyl-15-hydroxymethylene-n-octacos-5,8,20-triene-10β,18α- diol-10β-D-glucopyranoside (1), along with the three known compounds, 3-epibetulinic acid (2), n-pentadecanyl octa-dec-19-en-oate (3) and β-sitosterol (4) were isolated from the methanolic extract of the cultured Catharanthus roseus hairy roots. The structures of the one new and three known compounds were elucidated using one- and two-dimensional NMR in combination with IR, EI/MS, FAB/MS. To the best of our knowledge, 3,7,11,19,23,27-hexamethyl-15-hydroxymethylene-n-octacos-5,8,20-triene-10β,18α-diol-10β-D-glucopyranoside, 3-epibetulinic acid and n-pentadecanyl octa-dec-19-en-oate were identified for the first time from the hairy roots of C. roseus.

• Bulletin of the Korean Chemical Society
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• 제27권1호
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• pp.93-98
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• 2006

Two new compounds 1'-(stigmast-11,20(21),25-trien 3$\alpha$,9$\alpha$-diolyl)-3'-(pimara-11,15-dien-3$\alpha$-olyl) glycerol (1) and stigmast-5-en-3$\alpha$,26-diol (2) along with known fatty acids n-hexacosanoic acid (3) and hexadecanoic acid (4), have been isolated from the methanol extract of rice hulls of Oryza sativa. The structures of the compounds were elucidated using 1D and 2D NMR spectral methods, viz; $^1H, ^{13}C, ^{13}C$-DEPT, $^1H-^1H$ COSY, $^1H-^{13}C$ HETCOR, HSQC and HMBC aided by IR, EIMS, FABMS and HRFABMS. Compound (1) showed inhibition to radish germination, growth of shoot and root length.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2001년도 추계학술발표회 초록집
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• pp.56-56
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• 2001

Ni-W alloy deposit is one of the best alternatives to hard chromium plating because of its good mechanical properties (high hardness, high strength, and good wear resistance). Ni-W alloy is deposited from weakly acidic or alkaline electrolytic bath with nickel sulfate, sodium tungstate or APT, and some kinds of organic hydroxy-acid complex and ammonia salts. W content of the deposit can be changed from 0 to 5Owt% and the coating with high W content is more attracted. But, meanwhile, the deposited layers are always found high internal stress, which cause them to become brittle and to bond insufficiently with the substrate. On the second hand, as the W content is incresed, the current efficiency reduced, which results in large quantities of hydrogen evolution and then produces bubbles on surface and pitting appearance In this paper, the influence of some additives on Ni-W alloy electroplating was investigated by means of compositional analysis and SEM. The initial results showed that 2-butyne-1,4-diol was the best brightener for Ni-W plating process. It could brighten and level deposit, but decreased the cathodic current efficiency. Its optimum concentration range is from O.lgjL to 0.5gjL. Besides, three kinds of additives including 2-butyne-1,4-diol were examined with Dagguchi method.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제31회 추계학술대회논문집
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• pp.231-236
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• 2008

양이온 개환중합법을 이용하여 Epichlorohydrin(ECH)과 Tetrahydrofuran(THF)을 공중합 하였다. 중합은 1,4-Butandiol 존재 하에 $BF_3THF$를 촉매로 사용하여 잘 제어된 Copolyetherdiol을 합성하였다. 분자량은 [monomer]/[diol]비를 조절하였고, 공중합체 조성은 ECH와 THF의 투입몰비를 변화하여 조절하였다. 합성된 Copolyetherdiol의 Chlorine기는$S_N2$반응을 이용하여 Azide기로 치환하였다. 합성된 고분자를 프리폴리머로 사용하여 경화제인 N-100/IPDI와 경화촉매인 TPB/MA 혼합촉매를 이용하여 Polyurethane을 합성하여 경화거동과 기계적 특성은 비교 분석하였다.

• 약학회지
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• 제29권2호
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• pp.76-89
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• 1985

The effects of ginseng saponin on the activity, phosphorylation, [$^{3}$H] ouabain binding and light scattering (disruption) of purified $Na^{+}$ ,$K^{+}$ -ATPase isolated from the outer medulla of sheep kidney were compared to those of gypsophila saponin, sodium dodecylsulfate (SDS), and Triton X-100 on the same parameters. $Na^{+}$ , $K^{+}$ -ATPase activity, phosphorylation, and [$^{3}H$] ouabain binding were inhibited by ginseng saponin (triol>total>diol), SDS, or Triton X-100, but increased by gypsophila saponin. Low doses of ginseng saponin (3.mu.g saponin/.mu.g protein) decreased phosphorylation sites and ouabain binding site concentration (Bmax) without any change of turnover number and affinity for ouabain binding which were decreased by high dose of ginseng saponin (over 10.mu.g saponin/.mu.g protein), SDS or Triton X-100. On the other hand, gypsophila saponin increased the affinity without any change of Bmax for ouabain binding. Inhibition of $Na^{+}$ ,$K^{+}$ -ATPase activity by ginseng saponin and SDS or Triton X-100 appeared before and after decrease in light scattering, respectively. These data suggest that ginseng saponins (total, diol, triol saponin) inhibit $Na^{+}$ , $K^{+}$ -ATPase activity by specific direct and general detergent action at low and high concentrations, respectively, and this inhibitory action of ginseng sapornin to $Na^{+}$ , $K^{+}$ -ATPase is not general action of all saponins.