• Journal of the Korean Applied Science and Technology
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• v.18 no.2
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• pp.103-110
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• 2001

Resource recovery and recycling of materials and products, including polyurethanes is viewed as a necessity in today's society. Most urethane polymers are made from a polyol and a diisocyanate. these and be chemicals such as water, diamines or diols that react with isocyanate groups and add to the polymer backbone. The problems of recycling polyurethane wastes has major technological, economic and ecological significance because polyurethane itself is relatively expensive and its disposal whether by burning is also costly. In general, the recycling methods for polyurethane could be classified as mechanical, chemical and feedstock. In the chemical recycling method, there are hydrolysis, glycolysis, pyrolysis and aminolysis. This study, the work was carried out glycolysis using sonication ant catalyzed reaction. Different kinds of recycled polyols were produced by current method(glycolysis), catalyzed reaction and sonication as decomposers and the chemical properties were analyzed. The reaction results in the formation of polyester urethane diols, the OH value which is determined by the quantity of diol used for the glycolysis conditions. The glycolysis rates by sonication for the various glycols, increased as fallows: PPG

• Polymer(Korea)
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• v.35 no.6
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• pp.526-530
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• 2011

Furan-2,5-dicarboxylic acid (FDCA) was synthesized by $KMnO_4$ oxidation of 2,5-dihydroxymethylfuran(DHMF) derived from biomass. Polyesters were synthesized by esterification and polycondensation of FDCA with various diols(ethane-1,2-diol, propane-1,3-diol, butane-1,4-diol, hexane-1,6-diol, decane-1,10-diol). The composition of polyesters was characterized by using $^1H$ NMR. Thermal properties of the polyesters were characterized by DSC and TGA. Intrinsic viscosities(IV) of the polyesters were measured to be 0.78~1.2 dL/g comparable with IV of commercial poly(ethylene terephthalate)(PET). As the chain lengths of diols increased, Young's modulus and strength decreased and elongation-to-break generally increased. Young's modulus and strength of the polyesters were measured to be 3551 MPa and 103 MPa, respectively, comparable with commercial PET.

• Textile Coloration and Finishing
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• v.31 no.3
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• pp.165-176
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• 2019

Polyurethane-ureas(PUUs) were prepared from 4,4'-methylenebis(cyclohexyl isocyanate) and various diols including isosorbide. Isosorbide is starch-derived monomer that exhibit a wide range of glass transition temperature and are therefore able to be used in many applications. PUU was synthesized by a pre-polymer polymerization using a catalyst. Successful synthesis of the PUU was characterized by fourier transform-infrared spectroscopy. Thermal properties were determined by differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. It was found that by tuning isosorbide content in the resin, their glass transition temperature(Tg) slightly decreased. Physical properties were also determined by tensile strength and X-ray diffraction. There is no significant differences between petroleum-derived diol and isosorbide in XRD analysis. Moreover, their physical and optical properties were determined. The result showed that the poly(tetramethylene ether glycol)/isosorbide-based PUU exhibited enhanced tensile strength, transmittance, transparency and biodegradability compared to the existing diols. After 11 weeks composting, the biodegradability of blends increased in ISB-PUU. The morphology of the fractured surface of blend films were investigated by scanning electron microscopy.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.435-438
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• 2003

Epoxide hydrolase(EH) catalyze the enantioselective hydrolysis of racemic epoxides to corresponding diols. A recombinant Pichia pastoris with EH from Rhodotorula glutinis has been constructed by reverse transcriptase-polymerase chain reaction(RT-PCR). The recombinant biocatalyst enantioselectively hydrolyze (R)-styrene oxide faster than (S)-enantiomer. The catalytic activity of recombinant biocatalyst was 7-fold higher than that of wild-type strain. The recombinant EH biocatalyst can be used for kinetic resolution for the production of enantiopure styrene oxide.

• Journal of the Korean Society of Tobacco Science
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• v.9 no.2
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• pp.77-85
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• 1987

$\alpha$, $\beta$-4.8.13-Duvatriene-1, 3-diols was identified as the major component of diterponoid extracted from Nicotiana Tabacum L. The isolated duvatriendiol was thermolyged at 300'c under a stream of nitrogen. The approximately 20 compounds were separated from the thermolyzates and the 9 compounds of them were identified with GC/MS. However, the thermolyzates identified in this study differed in distribution from the products under the condition of a different temperature or photooxidation.

• Polymer(Korea)
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• v.25 no.3
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• pp.343-348
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• 2001

The mechanical and the platelet adhesion properties of the fluorinated polyurethane elastomers synthesized with a perfluorinated polyether diol (Fomblin ZDOL$ZDOL^{(R)}$) and 4,4'-diphenyl methane diisocyanate (MDI) were investigated. The change of mechanical properties with the Fomblin content and the type of the polyether diol was investigated by applying a designed technique using in vitro platelet adhesion test. As a result, the tensile properties were affected by the content and the type of nixed polyether diols. Also the platelet adhesion of polyurethane elastomers decreased with increasing the extent of fluorination in the polymer.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2391-2396
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• 2011

Benzonaphthofurandiones containing four coplanar fused aromatic rings were synthesized and evaluated for their cytotoxicity against five human cancer cell lines, and their inhibitory activity on topoisomerases. These benzonaphthofurandiones were prepared by condensation of 2,3-dichloronaphthoquinone and three aromatic diols with base catalysts in alcohol. The synthesized compounds were o-alkylated with six dialkylaminoalkyl halides. The hydroxy derivatives (8a-8g) exhibited relatively potent cytotoxicity among the prepared compounds. These compounds were evaluated as excellent inhibitors against topoisomerase II (topo II). Especially, the hydroxy analogue with branched methyl side chain (8e) showed high cytotoxicity against cancer cell lines and good inhibitory activity on topo II.

• Journal of the Korean Society of Tobacco Science
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• v.22 no.1
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• pp.19-24
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• 2000

To obtain the genetic information about DVT( $\alpha$- and $\beta$-4,8,13- duvatriene-1,3-diols) and cis-abienol contents, two burley(Burley 21, KB 108), three sun-cured cultivars(N. tabacum L. cv. Yonbyun 3, Jahengyon and Jaraehong), TI 1068, and thirty F$_1$ hybrids derived from them were sampled and the diterpenes were analysed using thin layer chromatography (TLC) procedures. DVT exudation from the leaf scerface could Ie detected in all coltivars and F$_1$ hybrids tested. TI 1068 and Yonbyun 3 had cis-abienol exdudates. Burley 21, KB 108, Jaheungyon, and Jaraehong had no spot of cis-abienol. It is considered that cis-abienol exdudation might be controlled by dominant gene(s). The cytoplasmic effect on the cis-abienol exdudation was not detected.

• Applied Biological Chemistry
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• v.40 no.6
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• pp.588-592
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• 1997

The new type ligand, bisphosphonites, were easily prepared through ligand exchange reaction of bis (diethylamino)phosphine with diols. These bisphosphonites reacted with $(COD)^2Rh^+BF_4\;^-$ to corresponding bisphosphonite-rhodium(I) comlexes, of which X-ray crystallography was for the first time investigated. This organometallic compound was applicated in hydroformylation reaction as catalyst, and proved to be very effective one.

• YAKHAK HOEJI
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• v.26 no.2
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• pp.91-96
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• 1982

In an attempt to design prodrugs for the Derivatives of the Isothiocyanates R-N=C=S were synthesized eleven novel bis-dithiocarbamates. The best way of preparing the dithiocarbamates was the formation of the dithiocarbonates followed by the reaction of the dithiocarbonates with amines. Thus, the treatment of the diols with carbon disulfide in the presense of potassium hydroxide afforded the potassium salts of the ditniocarbonic acids. The potassium salts were then reacted with alkyl halides to give the dithiocarbonates, which upon treatment with amines produces the dithiocarbamates. In case of vicinal diol (n=o in the above formula), only one of the hydroxy groups was reacted to give the mono-dithiocarbonate. The dithiocarbonates failed to react with amides and aromatic amines. Dithiocarbonates of the different types were obtained when the active double bonds, such as $CH_{2}=CH-Z$ , (Z are electron withdrawing groups), were allowed to react with the free dithiocarbonic acids produced in situ by carefully neutralizing the Potassium salts of the corresponding acids. These compounds are considered to be of some value as prodrugs for the active double bonds.