• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.1-4
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• 1998

Segmented Polyurethanes Elastomers are a class of polymers having interesting properties which arise from their unique phase-separated structures resulting from the thermodynamic incompatibility of the ingredients[1]. Segmented polyurethane Elastomer generally consists of a segment derived from a polymeric diol and a hard segment from a diisocyanate and a low molecular weight diol(chain extender).(omitted)

• Journal of the Korean Wood Science and Technology
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• v.29 no.3
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• pp.99-103
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• 2001

Three flavan-3,4-diol derivatives were isolated from the heartwood of Robinia pseudoacacia and characterized by spectroscopic methods including $^1H$ and $^{13}C$ NMR and positive FAB-MS. The structures were identified as 4,4'-dimethoxy-, 4-ethoxy- and 4-ethoxy-4'-methoxy-2,3-trans-3,4-cis-(+)-leucorobinetinidin.

• Archives of Pharmacal Research
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• v.13 no.2
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• pp.201-203
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• 1990

The efficient synthetic routes to cis-1-ethenyl-2-hydroxymethyl-cyclohexane, an useful synthetic intermediate, have been described. Access to the cis-disubstituted cyclo hexane is gained through the Clasen rearrangment and selective DHP protection of diol respectively.

• YAKHAK HOEJI
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• v.43 no.1
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• pp.11-15
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• 1999

A brief route for regiospecific synthesis of novel 10-Oxodaunomycinone Derivatives (10a, b) is described. Dimethoxy-l-tetralone 4 was converted to acetyl tetralone (5a, b) which was oxidized with oxygen to obtain cis-diol compound (8a, b). The construction of (10a, b) was completed by the condensation of phthaloyl dichloride 9 with cis-diol (8a, b)

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.237.1-237.1
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• 2003

(2S 3R. 4E) 5-Aryl-4-pentene-1,3-diol-2-aminoueras had been synthesized for their cytotoxic activity. Pinene was oxidized with KMnO4 to give 2-hydroxy-3-pinanone. which treated with ethyl glycinate to yield iminoglycinate and then reacted with aldehyde derivatives and titanium enolate to afford 3-hydroxy aldol compounds. (omitted)

• Journal of Food Hygiene and Safety
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• v.22 no.4
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• pp.306-310
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• 2007

As a preliminary study for risk assessment of 3-monochloropropane-1,2-diol (3-MCPD) from processed food, the levels of 3-MCPD in commercial sauces and instant fried noodle (ramyun) seasoning were analyzed with gas chromatography/mass spectrometry. In August and September 2005, twenty-five samples of commercial sauces and twenty-five samples of instant fried noodle (ramyun) seasoning were collected from retail outlets and markets in Seoul, Korea. Six out of twenty-five sauces contained 3-MCPD and the highest concentration was 0.045 mg/kg. On the basis of per capita consumption of sauces and mean concentration of 3-MCPD, the estimated daily exposure to 3-MCPD from sauces was $0.094{\mu}g/person/day$. None of the twenty-five instant fried noodle (ramyun) seasoning samples was contained 3-MCPD. Therefore consumption of instant fried noodle (ramyun) seasoning was estimated not to contribute dietary exposure to 3-MCPD.

• Polymer(Korea)
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• v.25 no.3
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• pp.421-426
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• 2001

11-Aminododecanoic acid, to insert the functional group of -COOH reacted with the end group of poly($\varepsilon$-caprolactone) diol, and cetyltrimethylammonium bromide (CTMA), to increase the d-spacing of Montmorillonite (MMT), were intercalated into $Na^+;_-$MMT. The modified MMT was reacted with poly(${varepsilon}-caprolactone$) diol ($M_n{=2000$) in THF solution at $80^{\circ}C$ for 4 hrs. After reaction, poly(${varepsilon}-caprolactone$) ($M_n{=80000$) was mixed into the solution for 12 hrs. To prepare the PCL/clay nanocomposite film this solution was cast into the silicon mold at $60^{\circ}C$ in vacuum oven for 6 hrs. From the results of XRD and TEM, it was found that the exfoliated PCL/clay nanocomposite were prepared. The effects of the amount of MMT on the mechanical properties and thermal properties of PCL/clay nanocomposites have been investigated by tensile tester and DSC. Because the MMT was dispersed homogeneously in PCL matrix, the Young's modulus of the nanocomposite were found to be excellent. However, MMT dispersed in PCL matrix had almost no effect on the tensile strength of the composites. The crystallization temperature of PCL increased in proportion to 3 wt% MMT in the PCL matrix.

• Journal of the Korean Chemical Society
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• v.27 no.1
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• pp.58-65
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• 1983

The mechanical properties (tensile strength, 100% modulus and hardness) of the urethane elastomers prepared from hydroxyl terminated polybutadiene (HTPB), several low molecular weight diols (ethylene glycol, 1, 3-propane diol, 1,4-butane diol, 1,5-pentane diol and 1,6-hexane diol) and two kinds of diisocyanates(TDI: toluene diisocyanate, IPDI: isophorone diisomechanical properties were enhanced for the increases of the concentrations of the urethane group, as predicted. In case of TDI, when the mechanical properties of the elastomers were plotted patterns were observed, which can be explained by hydrogen bondings depending on the number of the methylene carbons. But the mechanical properties of the elastomers derived from IPDI had decreasing curves against the number of methylene carbons in low molecular weight diols, without the characteristic zigzag patterns.

• Biomedical Science Letters
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• v.12 no.3
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• pp.241-247
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• 2006

To evaluate an effect of pathological liver damage on the cyclohexane (CH) metabolism, rats were pretreated with 50% carbon tetrachloride $(CCl_4)$ dissolved in olive oil (0.1ml/100g body weight) 10 or 17 times intraperitoneally at intervals of every other day. To these liver damaged animals, CH (a single dose of 1.56g/kg body weight, i.p.) was administered at 48hr after the last injection of $CCl_4$. The CH metabolites; cyclohexanol (CH-ol), cyclohexane-l,2-diol (CH-l,2-diol) and cyclohexane-l,4-diol (CH-l,4-diol) and cyclohexanone (CH-one) were detected in the urine of CH treated rats. After CH treatment, the serum levels of CH-ol and CH-one were remarkably increased at 4 hr and then decreased at 8hr in normal group. Whereas in liver damaged rats, these CH metabolites were higher at 8hr than at 4hr. The excretion rate of CH metabolites trom serum into urine was more decreased in liver damaged animals than normal group, with the levels of excretion rate being lower in $CCl_4$ 17 times injected animals than 10 times injected ones. It was interesting that the urinary concentration of CH metabolites was generally more increased in liver damaged animals than normal ones, and the increasing rate was higher in $CCl_4$ 17 times injected rats than 10 times injected ones. Taken all together, it is assumed that reduced urinary excretion rate of CH metabolites in liver damaged rats might be resulted from deteriorated hepatic and renal blood flow, and an increased urinary excretion amount of CH metabolites in liver damaged rats might be caused by reduced expiration amount of the metabolites due to lung damage.

• Journal of the Korean Chemical Society
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• v.23 no.3
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• pp.180-185
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• 1979

Electrochemical reduction behavior from 2-butyne-1, 4-diol (BID) to 2-butene-1,4-diol (BED) by the use of various cathodes, such as Ti, Zr, Ni, Pt, Cu, Ag, Au, Zn, Hg, Pb and graphite has been studied. It has been found that cathodic polarization curve with metal of IB subgroup such as Cu, Ag and Au consisted of one wave in BID-alkaline solution, whereas it was not formed any wave in BED solution. Therefore, it was found that the cathode which was the most suitable in order to proceed in this reaction was Cu, Ag and Au. At cyclic voltammetry using a silver cathode in BID-alkaline solution, the current of the peak was proportional to square root of the sweep rate of potential and also proportional to concentration of BID. Activation energy was calculated for 3.75 kcal/mole from the plot of log $I_l$ vs. 1/T. Consequently, the reduction current of BID with a silver cathode in alkaline solution was found the diffusion current.