• Journal of Adhesion and Interface
• /
• v.11 no.1
• /
• pp.3-8
• /
• 2010

Thermal properties, flame retardant property, and sound-damping properties of polyurethane (PU) nanocomposite foams prepared with oligomeric 1,2-propanediol isobutyl polyhedral silsesquioxane (POSS) were investigated. It was found that the PU nanocomposite foams showed good sound-damping performances comparing to the PU foams without POSS.

• Bulletin of the Korean Chemical Society
• /
• v.17 no.4
• /
• pp.362-365
• /
• 1996

Carbonyl compounds 1, alkyl- and arylaldehydes and alkyl, aryl, benzylic, and cyclic ketones were converted to the corresponding 1,3-dioxolanes 2 and 1,3-dioxanes 4 with ethylene glycol and 2,2-dimethyl-1,3-propanediol in the presence of 1-3 mol% of 1-(p-substituted)benzyl-1,1-dimethyl-2-(p-substituted)-benzoyl hydrazinium hexafluoroantimonates 3 in high yields.

• Toxicological Research
• /
• v.31 no.3
• /
• pp.313-319
• /
• 2015

3-Monochloro-1,2-propanediol (3-MCPD) and 1,3-dichloro-2-propanol (1,3-DCP) are not only produced in the manufacturing process of foodstuffs such as hydrolyzed vegetable proteins and soy sauce but are also formed by heat processing in the presence of fat and low water activity. 3-MCPD exists both in free and ester forms, and the ester form has been also detected in various foods. Free 3-MCPD and 1,3-DCP are classified as Group 2B by the International Agency for Research on Cancer. Although there is no data confirming the toxicity of either compound in humans, their toxicity was evidenced in animal experimentation or in vitro. Although few studies have been conducted, free 3-MCPD has been shown to have neurotoxicity, reproductive toxicity, and carcinogenicity. In contrast, 1,3-DCP only has mutagenic activity. The purpose of this study was to analyze 3-MCPD and 1,3-DCP in various foods using gas chromatography-mass spectrometry. 3-MCPD and 1,3-DCP were analyzed using phenyl boronic acid derivatization and the liquid-liquid extraction method, respectively. The analytical method for 3-MCPD and 1,3-DCP was validated in terms of linearity, limit of detection (LOD), limit of quantitation, accuracy and precision. Consequently, the LODs of 3-MCPD and 1,3-DCP in various matrices were identified to be in the ranges of 4.18~10.56 ng/g and 1.06~3.15 ng/g, respectively.

• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.598-598
• /
• 2003

• Korean Chemical Engineering Research
• /
• v.47 no.6
• /
• pp.768-774
• /
• 2009

To improve the productivity of 1,3-propanediol(1,3-PD) with K. pneumoniae DSM4799 using pure glycerol and crude glycerol derived from the biodiesel process, optimizing fermentation conditions was performed by changing environmental factors such as anaerobic/aerobic condition, temperature, glycerol concentration, and pH. When anaerobic conditions were maintained, there was an improved 1,3-PD production compared with that from aerobic/anaerobic 2-stage fermentation. From the results with temperature $26{\sim}37^{\circ}C$, the higher 1,3-PD production yield was observed at $30{\sim}33^{\circ}C$. For an initial glycerol concentration higher than 60 g/L, cell growth and 1,3-PD production were inhibited. When crude glycerol was used, the initial 1,3-PD production appeared to be inhibited. After 48 hr of incubation, however, 1,3-PD production with crude glycerol was even higher than that with pure glycerol, demonstrating the feasibility of 1,3-PD production using crude glycerol as a substrate. Fed-batch fermentation was applied for the high concentration of 1,3-PD without substrate inhibition. By regulating pH at 7 during the fed-batch with glycerol lower than 40 g/L, the yield of 1,3-PD was 25% higher than that without pH regulation(0.56 g/g vs. 0.45 g/g). In conclusion, based on our results, anaerobic conditions, temperature at $30^{\circ}C$, pure or crude glycerol lower than 40 g/L, and pH regulation at 7 were the optimized conditions for 1,3-PD production using K. pneumoniae DSM4799, making it more feasible to produce 1,3-PD at higher concentration and a lower price.

• Korean Journal of Food Science and Technology
• /
• v.29 no.1
• /
• pp.183-187
• /
• 1997

The analytical conditions of 1,3-dichloro-2-propanol (DCP) and 3-chloro-1,2-propanediol (MCPD) by solid phase extraction were optimized to improve recovery. Selected-ion monitoring technique which was used for GC-MS analysis of both compounds gave substantially higher sensitivity. The detection limits of DCP and MCPD were 25 and 50 ppb, respectively. The effects of extraction column type, elution solvent and salt concentration on recovery were examined. A normal phase column was better than a reverse phase column in solid phase extraction of DCP and MCPD. It was explained in terms of polarity relationship of solvent-solute-solid phase. A maximum recovery was obtained at the salt concentration of 20% (w/v). Water-immiscible and chloropropanol-soluble solvents such as chloroform, diethyl ether, hexane and ethyl acetate were tested for elution solvent. Hexane and ethyl acetate were the most suitable solvents for the extraction of DCP and MCPD, respectively. High recovery better than 95% was obtained with the selected solvents.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.24 no.2
• /
• pp.219-227
• /
• 1995

Natto is a Japanese tradiational food made from whole soybeans by the fermentation of Bacillus natto. This study was attempted to improve the taste of Natto, garlic(2%) and red pepper oleoresin(0.2%) were added. Conventional Natto(N-1), garlic Natto(N-2), red pepper oleoresin Natto(N-3), garlic and red pepper oleoresin Natto(N-4) were prepared. Volatile flavor components, fatty acid, organic acid, pH and titratable acdity in all samples were investigated. The experimental results revealed the presence of 62 volatile components in conventional Natto. Among there, the major flavor compounds were identified to be 2, 5-dimethylpyrazine, trimethyl-pyrazine, 2, 6-bis91, 1-dimethylethyl) phenol. Seventy-one volatile compounds were detected in N-2, and major compounds were identified to be methyl-2-propenyl disulfide, 2, 6-bis(1, 1-dimethylethyl)phenol and 2, 5-dimethylpyrazine. The amounts of volatile compounds, 2-methyoxyphenol and 1, 2-benzenedicarboxylic acid increased by addition of garlic, where as, 1,2 -propanediol, 1-hexanol and 2, 5-dimethylpyrazine decreased. The compounds, 4, 5-dihydroxy-5-propyl-1H-pyrazole, 1, 1, 3-trimethylcyclopentane were identified in N-3. The compounds, such as trimethylpyrazine, 3-ethyl-2,5-dimethylpyrazine increased by addition of red pepper oleoresin, whereas 1,2-propanediol, 1-hexanol and 2,5-dimethylpyrazine decreased. Fatty acid compositions were mainly consisted of linoleic acid(43.66~55.89%) and followed by oleic, palmitic, linolenic, stearic, arachidic, myristic acid. The organic acids we4re identified to be citric(28.2~30.6), acetic(50.0~73.3) and pyroglutamic acid(2.1~3.7).

• YAKHAK HOEJI
• /
• v.30 no.3
• /
• pp.121-127
• /
• 1986

Three new alkanol esters of d-2-(6-methoxy-2-naphthyl)propionic acid, NAPROXEN were synthesized by esterification of sodium naproxen with chloralcohols, such as 2-chloroethanol, 3-chloro-1, 2-propanediol and $\beta$-chloroethoxyethanol in dimethylformamide. These new esters were obtained with comparably high yield and identified by elemental analysis, UV, IR and NMR techniques.

• Clinical and Experimental Reproductive Medicine
• /
• v.20 no.1
• /
• pp.31-36
• /
• 1993

The effects of freezing and 1,2-propanediol on early and late pronucleate stage mouse ova were investigated in terms of survival after thawing and development in vitro. The samples were divided into two groups according to different age in pronucleate ova: ova in(1) early pronuclear stage with two distant pronuclei at 18h after hCG injection, and (2) late pronuclear stage with adjacent pronuclei at 30h. Zygotes in the late pronuclear stage have been proven to be more resistant to 1,2-propanediol, showing a significantly higher developmental rate than zygotes in early stage (80.3 versus 66.3%, <0.05), but survival rate was similar in the two groups (91.0 versus 93.5%). After freezing and thawing, survival and developmental rates were decreased in both groups when compared to the control group (54.3 versus 92.3%, 47.7 versus 73.3%. respectively). And developmental rate in the late pronuclear stage zygotes showed significantly higher than in early (55.4 versus 40.0%) after thawing. In conclusion, early pronucleate mouse ova have a lower developmental capacity in vitro and a lower survival rate after freezing and thawing than late ova. These findings suggest that the timing of freezing could be important for survival and further development in vitro in cryopreservation of human pronucleate ova.

• Journal of Korean Society for Atmospheric Environment
• /
• v.23 no.5
• /
• pp.539-546
• /
• 2007

Increasing emission of $CO_2$ significantly effects the global warming. Chemical absorption is one of separation methods of $CO_2$ from the industrial flue gases. In this study, the $CO_2$ removal efficiency as well as the $CO_2$ absorption amount of aqueous AMP (2-amino-2-methyl-1-propanol) solutions were measured using the continuous absorption and regeneration apparatus. We investigated the effect of aqueous AMP+AEPD(2-amino-2-ethyl-1, 3-propanediol) and AMP+TIPA (triisopropanolamine) solutions to enhance absorption characteristics of AMP. As a result of this study, the absorption amount and $CO_2$ removal efficiency were increased with adding TIPA into 30 wt.% AMP. The absorption amount and $CO_2$ removal efficiency of aqueous 30 wt.% AMP+5 wt.% TIPA solution were $1.70\;kg-CO_2/kg-absorbent$ and 91.1%, while those of aqueous 30 wt.% AMP solution were $1.58\;kg-CO_2/kg-absorbent$ and 89.3%. In addition, aqueous 30 wt.% AMP+5 wt.% TIPA solution used in the study revealed the high stripping efficiency, which was almost 98%, at the temperature of $110^{\circ}C$. Thus, the temperature of regenerator should be operated at $110^{\circ}C$.