• Title/Summary/Keyword: mercaptan

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Adsorption characteristics of tert-Butyl Mercaptan on Impregnated Activated Carbon (첨착활성탄을 이용한 tert-Butyl Mercaptan의 흡착특성 연구)

  • Kim S. B.
    • Journal of the Korean Institute of Gas
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    • v.7 no.1 s.18
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    • pp.47-52
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    • 2003
  • The adsorption characteristics of rert-butyl mercaptan(TBM) on base activated carbon and activated carbon impregnated with $CuCl_2$ or KI were studied. Adsorption of TBM on the surface of the KI or $CuCl_2$ impregnated activated carbon was detected by gas chromatograph equipped with a flame photometric detector. The amount of adsorption on those impregnated carbon found to be 7 or 8 times greater than on the non-impregnated activated carbon and varied according to the concentration of impregnated metal. FT-IR measurement showed that major reaction occuring on the surface of the catalytic adsorbent was dimerization of TBM into di-tert-butyl disulfide which had no stench.

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Removal of Odor- containing Sulfur Compound, Methyl Mercaptan using Modified Activated Carbon with Various Acidic Chemicals (산으로 개질된 활성탄을 이용한 메틸 메르캅탄 악취물질 제거)

  • Kim Dae Jung;Seo Seong Gyu;Kim Sang Chai
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.2
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    • pp.155-160
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    • 2005
  • Removal of methyl mercaptan was investigated using adsorption on virgin activated carbon (VAC) and modified activated carbons with acidic chemicals in the present work. CAC, NAC, AAC and SAC were represented as activated carbons modified with HCI, HNO$_{3}$, CH$_{3}$COOH and H$_{2}$S0$_{4}$ ,respectively The pore structures were evaluated using nitrogen isotherm. The surface properties of virgin activated carbon and modified activated carbons were characterized by EA, pH of carbon surface and acid value from Boehm titration. The modification of activated carbon with acidic chemicals resulted in a decrease in BET surface area, micropore volume and surface pH, but an increase in acid value. The order of the adsorption capacity of activated carbons was NAC>AAC>SAC>CAC>VAC, and in agreement with that of acid value of activated carbons, whereas in disagreement with that of micropore volume of activated carbons. It appeared that chemical adsorption played an important role in methyl mercaptan on modified activated carbons with acidic chemicals compared to virgin activated carbon. Modifying activated carbon with acidic chemicals enabled to significantly enhance removal of methyl mercaptan.

The Kinetics and Mechanism of Nucleophilic Addition of Mercaptan to a ${\beta}$-Nitrostyrene in Acidic Media (I) (${\beta}$-Nitrostyrene에 대한 Mercaptan의 親核性 添加反應에 關한 硏究 (I))

  • Park, Ok-Hyun
    • Journal of the Korean Chemical Society
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    • v.12 no.3
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    • pp.106-113
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    • 1968
  • The rate-constants of the nucleophilic addition reaction of n-butylmercaptan to 3,4-methylenedioxy-${\beta}$-nitrostyrene were determined at various acidic pH and a rate equation which can be applied over wide pH range was obtained. From this equation, one may conclude that this reaction is started by addition of mercaptan molecule below pH 3, while above pH 6, the overall rate of addition is almost only depend upon the concentration of nitrostyrene and the mercaptide ion. At pH 3∼6, the complex mechanism of this addition reaction can also be fully explained by the rate equation.

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Extrathermodynamic Relationships for the Nucleophilic Addition Reaction of Mercaptan to a Carbon Double Bond (炭素二重結合에 대한 Mercaptan의 친핵성 첨가 반응의 Extrathermodynamic Relationship에 관한 연구)

  • OK-HYUN PARK;TAE-SUP UHN
    • Journal of the Korean Chemical Society
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    • v.13 no.4
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    • pp.297-302
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    • 1969
  • The activation parameters for the nucleophilic addition reactions of n-propyl-, n-butyl-, n-amyl-and n-hexyl-mercaptan to 3, 4-methylene-dioxy-${\beta}$-nitrostyrene were determined at pH 5.8 and pH 2.0, and also the isokinetic temperature of the reactions at pH 5.8 was obtained numerically 262${\circ}$K, and at pH 2.0, 17.1${\circ}$K. From the values obtained above, the fact that the mercaptan having the longer carbon chain has the greater nucleophilicity of it in the addition reactions has been discussed by the extrathermodynamic analysis of ${\Delta}H^{\neq}$and ${\Delta}S^{\neq}$.

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The Effects of Some Halitosis Removal Methods on the Reduction of Intraoral Volatile Methyl Mercaptan Concentrations (수종 구취제거법이 구강내 휘발성 메틸머캅탄 감소에 미치는 영향)

  • An-Hee Lee;Woo-Cheon Kee
    • Journal of Oral Medicine and Pain
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    • v.18 no.1
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    • pp.97-105
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    • 1993
  • In order to evaluate the effectiveness of tooth brushing, mouth gargling and gum chewing in reducing halitosis, 84 individuals ranging in age from 22 59 28 years old were examined. These individuals had no gross oral abnormalities, other than mild gingival inflammation, dental caries, nasopharyngeal disorder, or systemic diseases that were associated with halitosis. They were divided into a tooth brushing group, a mouth garging group, a gum chewing group and a control group that did not use any halitosis removing method. Each of the groups included 21 persons, B.B. Checker (Tokuyama Soda Col, LTDl, Japan) was used to measure the concentrations of intraoral volatile methyl mercaptan of each group. The concentrations of intraoral volatile methyl mercaptan were measured before and after lunch, and after removing halitosis by toothe brushing, mouth gargling and gum chewing. The obtained results were as follows : 1. The average concentration of intraoral volatile methyl mercaptan before lunch was 1.79ppm and after lunch it was 2.02ppm, an increase of 12.9%. 2. In the tooth brushing group the average concentration of intraoral volatile methyl mercaptan was 0.61ppm, in the mouth gargling group it was 1.15ppm, in the gum chewing group it was 1.64ppm and in the control group it was 1.92ppm. It decreased 69.5% in the tooth brushing group, 43.8% in the mouth gargling group, 18.4% in the gum chewing group and 5.4% in the control grop (p<0.05). 3. There were significant differences between the tooth brushing and control group, tooth brushing and gum chewing group and between mouth gargling and control group in concentrations of intraoral volatile methyl mercaptan after using the halitosis removing methods (p<0.05). According to the above results, tooth brushig and mouth gargling are effective ways to reduce halitosis.

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A Study on the Relationship between Halitosis Developments and Oral Environmental (구취발생과 구강환경의 연관성에 관한 연구)

  • Jee, Yun-Jeong;Kim, Jung-Sool;Lee, Jung-Hwa;Jeon, Eun-Suk
    • Journal of dental hygiene science
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    • v.10 no.2
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    • pp.101-107
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    • 2010
  • The purpose of this study was to analysis know the important oral environmental factors which affect halitosis components of the adult in order to provide basic data for halitosis prevention and establish a device to eliminate halitosis efficiently. The 97 adults who visited at the Dental Clinic in Metropolis (M=68, F=30) participated in this study that performed from March in 2009 to in 2010. The obtained results through items as caries status, periodontal status, salivary flow, the viscosity, pH, Snyder test, plaque deposit, tongue plaque and halitosis check were as followings. The average shame of halitosis components appeared at hydrogen sulfide 36.71 ppb methyl mercaptan 31.46ppb dimethyl sulfide 54.33 ppb and Ammonia 22.60 ppm. The normality and the detection comparative result dimethyl sulfide above reverse appeared highly at 46.9%, ammonia appeared highly at 52%. According to the Hydrogen sulfide level was a high relationship among age, CPI, tongue coat status, DMFT index which were statistically significant (p<0.05). According to the quantity of hydrogen sulfide level there was relationship where tongue coat status Saliva flow rate considers statistically(p<0.05). The quantity of methyl mercaptan level there was relationship where Dimethyl sulfide level, tongue coat status, Saliva flow rate considers statistically(p<0.05). The quantity of Dimethyl sulfide level there was relationship where Hydrogen sulfide level, ammonia level, tongue coat status, Saliva pH and Saliva flow rate considers statistically(p<0.05). Ammonia level there was relationship where Methyl mercaptan level, CPI, and Saliva flow rate considers statistically(p<0.05).

Mechanical Properties of Low Temperature and Fast Cure Epoxy with Various Mercaptans (Mercaptan 경화제에 의한 저온속경화 에폭시의 열적 기계적 물성)

  • Kim, Won Young;Eom, Se Yeon;Seo, Sang Bum;Lee, Kee Yoon
    • Polymer(Korea)
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    • v.37 no.5
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    • pp.557-562
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    • 2013
  • The thermal expansion and mechanical properties of diglycidyl ether of bisphenol A (DGEBA) with mercaptan hardeners were studied by a comparative method with an amine-adduct type hardener. Thermal expansion and dynamic mechanical properties were measured by thermo mechanical analysis (TMA) and dynamic mechanical ananlysis (DMA), respectively. The $T_g$ and the coefficient of thermal expansion (CTE) of epoxy/amine-adduct type hardener system were $82.6^{\circ}C$ and 71.2 $ppm/^{\circ}C$, respectively. As the number of -SH functional group of mercaptan hardener increased, the $T_g$ rapidly decreased and gradually increased up to ca. $80^{\circ}C$ and the CTE under the $T_g$ rapidly increased to ca. 200 $ppm/^{\circ}C$ from 80 $ppm/^{\circ}C$ and decreased to ca. 100 $ppm/^{\circ}C$. The crosslinking density of epoxy with amine-adduct type hardener was ca.1.5 $mol/cm^3$, while that of epoxy with mercaptan hardeners increased from 1.0 to 1.7 $mol/cm^3$, as the number of -SH functional group increased. The storage modulus can increase up to 2700MPa at $30^{\circ}C$.