• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.1
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• pp.79-92
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• 2019

Titanium hydride potassium perchlorate (THPP) is one of the commonly utilized pyrotechnic materials in aerospace industries. The current study elucidates the effects of hygrothermal aging on the combustion of THPP experimentally. First, applying the Differential Scanning Calorimetry (DSC) and isocoversional method, both the delay of reaction start and decrease in maximum reaction rate were observed. The kinetics parameters tended to fluctuate depending the thermal reaction or intermediate product formation of THPP. Also, the oxidants decomposition and fuel oxidation phenomenon were discovered by X-ray photoelectron spectroscopy (XPS). The experimental heat from DSC data were verified as reasonable by comparing with the theoretical heat obtained utilizing both THPP formulation from XPS and NASA Chemical Equilibrium with Applications (CEA). Both data had identical variation trend, which expecially had the highest heat value at 10 weeks aged sample.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.285-291
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• 1987

The approximate rates, stoichiometries and products of the reaction of potassium triethylborohydride $(KEt_3BH)$ with selected organic compounds containing representative functional groups under the standard condition $(0^{\circ}C,$ THF) were examined in order to explore the reducing characteristics of this reagent as a selective reducing agent. Primary alcohols, phenols and thiols evolve hydrogen rapidly whereas secondary and tertiary alcohols evolve very slowly. n-Hexylamine is inert to this reagent. Aldehydes and ketones are reduced rapidly and quantitatively to the corresponding alcohols. Reduction of noncamphor gives 3% exo- and 97% endo-norboneol. Anthraquinone is cleanly reduced to 9,10-dihydro-9,10-dihydroxyanthracene stage. Carboxylic acids liberate hydrogen rapidly and quantitatively but further reduction does not occur. Anhydrides utilize 2 equiv of hydride to give an equimolar mixture of acid and alcohol. Acid chlorides, esters and lactones are rapidly and quantitatively reduced to the corresponding alcohols. Epoxides are reduced at moderate rates with Markovnikov ring opening to give the more substituted alcohols. Primary amides liberate 1 equiv of hydrogen rapidly. Further reduction of caproamide is slow whereas benzamide is not reduced. Tertiary amides are reduced slowly. Benzonitrile utilizes 2 equiv of hydride in 3 h to go to the amine stage whereas capronitrile takes only 1 equiv. The reaction of nitro compounds undergo rapidly whereas azobenzene and azoxybenzene are reduced slowly. Cyclohexanone oxime rapidly evolves hydrogen without reduction. Phenyl isocyanate utilizes 1 equiv of hydride to proceed to formanilide stage. Pyridine N-oxide and pyridine is reduced rapidly. Disulfides are rapidly reduced to the thiol stage whereas sulfoxide, sulfonic acid are practically inert to this reagent. Sulfones and cyclohexyl tosylate are slowly reduced. Octyl bromide is reduced rapidly but octyl chloride and cyclohexyl bromide are reduced slowly.

• Bulletin of the Korean Chemical Society
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• v.29 no.11
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• pp.2303-2304
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• 2008

• Bulletin of the Korean Chemical Society
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• v.29 no.7
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• pp.1407-1408
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• 2008

• 한국전기화학회:학술대회논문집
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• 2003.07a
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• pp.183-187
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• 2003

Carbon nanotubes, prepared by the catalytic decomposition of acetylene at $700^{\circ}C$ over a Mm based $AB_5$ hydrogen storage alloy hydride catalysts, have been used as a support for platinum electrocatalysts. The performance of this electrocatalyst In proton exchange membrane fuel cells has been studied and discussed.

• Bulletin of the Korean Chemical Society
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• v.30 no.3
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• pp.695-699
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• 2009

A short and efficient synthesis of (2S,3S)-safingol from commercially available D-ribo-(2S,3S,4R)-phytosphingosine is described. The highlights of the synthesis are a stereoselective one-pot transformation of a diol into an epoxide under phase transfer catalytic conditions and a regioselective epoxide-opening reduction with a hydride reagent.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1592-1594
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• 2013

• Bulletin of the Korean Chemical Society
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• v.17 no.8
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• pp.720-724
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• 1996

Catecholalane (1,3,2-Benzodioxaluminole, CA) prepared from catechol and aluminum hydride in tetrahydrofuran (THF) is found to be a selective reducing agent. The systematic study in order to characterize the reducing properties of the reagent under practical conditions (THF, 0 or 25 ℃, the quantitative amount of reagent to compound) has been done. The reagent reduces aldehydes, ketones, esters and acid chlorides to the corresponding alcohols, and primary amides to the corresponding amines. Especially noteworthy is that the reagent can convert both aromatic and aliphatic nitriles to the corresponding aldehydes in very high yields.

• Bulletin of the Korean Chemical Society
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• v.8 no.3
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• pp.202-205
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• 1987

The reduction of some cyclic conjugated enones with electron-donating substituent on C-3 by sodium borohydride was accelerated on irradiation. The photo-enhanced reduction seems to undergo through zwitterionic species formed from the (n, ${\pi}^{\ast}$) triplet state of conjugated enones, followed by hydride attack to yield unsaturated or saturated alcohols.

• Journal of the Korean Chemical Society
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• v.38 no.12
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• pp.891-897
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• 1994

A method has been investigated for the determination of Selenium in Ginseng radix, Ganoderma Lucidum and Garlic using hydride generation atomic absorption spectrometry (HG-AAS). The effects of several acids and sodium tetrahydroborate concentration and their flow rate on the determination of Selenium for the hydride generation were investigated. The method of sample decomposition was also investigated using various mineral acids, such as nitric, perchloric and sulfuric acid in the closed system and foreign ion effects were studied. In the optimum conditions, we obtained calibration curve in the range 0-40 ppb. The analytical data of Garlic, Ganoderma Lucidum and Ginseng radix are 289, 296, 198 ppb, respectively.