• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.25-31
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• 2017

The flash point, explosion limits, autoignition temperature(AIT) are important combustible properties which need special concern in the chemical safety process that handle hazardous substances. For the evaluation of the flammable properties of n-butylacetate, this study was investigated the explosion limits of n-butylacetate in the reference data. The flash points, fire points and AIT by the ignition delay time of n-butylacetate were experimented. The lower flash points of n-butylacetate by using the Setaflash and Pensky-Martens closed-cup testers were $24^{\circ}C$ and $26^{\circ}C$, respectively. The flash points of n-butylacetate using the Tag and Cleveland open cup testers are measured $31^{\circ}C$ and $40^{\circ}C$, respectively. And the fire points of n-butylacetate by the Tag and Cleveland open cup testers were measured $32^{\circ}C$ and $41^{\circ}C$. The AIT of n-butylacetate measured by the ASTM 659E tester was measured as $411^{\circ}C$. The lower explosion limit of lower flash point $24^{\circ}C$, which was measured by the Setaflash tester, was calculated to be 1.40 vol%. Also, the upper explosion limit of upper flash point $67^{\circ}C$ the Setaflash tester was calculated to be 12.5 vol%.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.90-98
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• 1994

For elucidation of various parameters' effects on the reactive extraction of citric acids, citric-acetic-lactic acid system with various carriers, diluents, and modifiers were investigated. Carries used were secondary amines, tertiary amines, and solvation extract. Dileunts were n-butylacetate, methoisobutylketon(MIBK), kerosine, and xylene. Modifiers were TBP and isodecanol. The effects of temperature and pH in aquous phase were studied, and equilibrium constants for the reactive extraction were obtained. The re-extraction was performed by alkali solutions such as NaOH, $Na_2CO_3$, and $K_2HPO_4$. Based on the experiment Di-isotridecylamine(secondary amine ) gave higher degree of extraction and more selective than other extractants tested for the extraction of citric acid. N-butylacetate and TBP showed heigher performance for a diluent and modifier, repetitively. The degree of extraction was getting better with decreasing the pH in the aquous phase and the temperature of extraction system. The degree of re-extraction was getting higher with decreasing basicity in the stripping phase and the system temperature, and with increasing the concentration of alkali solution.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.121-126
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• 1994

To elucidate the effect on the reactive extraction of acetic acid, various carriers and modifiers were investigated. Carriers used were secondary and tertiary amines and solvation extractant. Diluent was n-butylacetate. Modifiers were 4-nonylphenol, TBP(Tti-n-butyl phospate) and isodecanol. Besides the effect of temperature and pH in aqueous phase were studied. The mixture of 50% tri-n-octyl/n-decylamine tertiary amine, gave higher degree of extraction and selectivity than other extractants in the extraction of acetic acid. It was found that 4-nonylphenol as modifier fairly good. The degree of extraction was higher with decreasing the pH in aquous phase and the temperature of extraction system.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.223-229
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• 1994

The effect of agitation speed on mass transfer coefficient in the extraction of citric acid from mixed aqueous solutions of citric and acetic acid with n-butylacetate solutions of di-isotridecylamine(DITDA) and 50% mixture of tri-n-octyl and try-n-hexyl phosphine oxide(MOHPO), were studied in batch extractor. Experimental results showed that the degree of extraction was higher with increasing agitation speed, and was best at 200rpm and 30 minutes in batch extractor. The higher degree of extraction was obtained in mixed solution of citric-acetic acid by using DITDA than MOHPO as an carrier. Mass transfer coefficient was proportional to the degree of extraction, and $K_r=1.254{\times}10^{-3}Re^{0.536}$ was found for she extraction of citric acid by DITDA.

• Journal of Environmental Science International
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• v.7 no.6
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• pp.753-759
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• 1998

In physical and reactive extraction of acrylic acid using various solvents the equilibrium characteristics of extraction were investigated. The degree of extraction in reactive extraction with Tri-n-octylamine(TOA) was 1.5~3 times than that in physical extraction. Distribution ratio was constant in methyl isobutyl ketone(MIBK) and n-butylacetate(n-BAc) but was increased with increasing the concentration of acrylic acid in benzene and chloroform. It can be explained by formation of dimers. Maximum extraction leadings of acrylic acid were three in benzene and were two in MIBK, chloroform and n-BAc, and it was found that acrylic acid was extracted as the form of $A_3$R In benzene and $A_2R$ in MIBK, chloroform and n-BAc. In effect of solvent, the degree of extraction was increased as he difference of solubility parameter of solvent and solute was decreased, and as dielectric constant of solvent was increased.

• Membrane Journal
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• v.3 no.3
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• pp.136-139
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• 1993

It is well known that the membrane permeation in pervaporation is governed by both the chemical nature of the membrane material and the physical structure of the membrane and also the separation can be achieved by differences in either solubility, size or shape. The solubility of the penerrant in the polymeric membrane can be described qualitively by applying the Hildebrand relation [1] which relates the energy of mixing of the penerrant and the polymer material. Froehling et al. have tried to predict the swelling behavior of polymers for the systems of polyvinylchloride(PVC)-toluene-methanol, PVC-trichloroethylene-nitromethane and PVC-n-butylacetate-nitromethane[2]. The former two systems which do not show the donor/acceptor interactions upon mixing showed the successful results[2]. In addition to this technique, there are several other possible approaches to predict the swelling behaviors of polymers, such as the surface thermodynamic approach[3, 4], the comparison of the membrane polarity with the solvent polarity in terms of Dimroth's solvent polarity value[5].

• Environmental Analysis Health and Toxicology
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• v.9 no.1_2
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• pp.37-51
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• 1994

To evaluate the genotoxicities of workers exposed to glue and glue cleaning solution, ambient air monitoring of working place, animal study and human monitoring were carried out. By GC-MS analysis, air samples collected from shoesmaking plant were found to be toluene, xylene, cyclohexane, n-hexane, methyl ethyl ketone, trichloroethylene, butylacetate, isopropyl alcohol. Glue and glue cleaning solution from shoesmaking plant were applicated topically to the CD-1 mice. DNA was isolated from skin 24 hr following the application and analysed for DNA-adducts using the nuclease $P_1$version of $^{32}$P-postlabelling assay. RAL (Relative Adduct Labelling, adducts$10^8$ nucleotides) was significantly increased in a dose-dependent manner in the glue cleaning solution treated mice skin. Peripheral blood DNA-adducts of workers exposed to glue and glue cleaning solution were also analysed by the same method, but there were not significant differences in the peripheral blood DNA-adducts level between exposed and control workers. In addition, glue cleaning solution from shoes factory was evaluated for mutagenicity in the Salmonella plate incorporation assay using strains TA 100 and TA 1535 in the presence and absence of Arochlor 1254-induced rat liver S$_{9}$. There was evident mutagenicity for cleaning solution in TA 100 regardless of $S_9$, but TA 1535 showed positive only in the absence of $S_9$when predicted by Stead model of mutagenicity prediction (p=0.0000). The urine concentrates from workers and controls were also assayed for mutagenicity towards strain TA 100 of Salmonella typhimurium in the presence of $S_9$ using Kado's microsuspension assay, but their mutagenic activities were not found to be significant. These data suggest that shoesmaking workers are exposed to genotoxic compounds and need to be monitored by testing the mutagenicity of human urines. However, $^{32}$P-postlabelling application requires further validation for the routine monitoring of human exposure.osure.

• Microbiology and Biotechnology Letters
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• v.8 no.1
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• pp.33-39
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• 1980

In order to invertigate penicillin acylase produced by a strain of Genus Escherichia, 47 strains of Genus Escherichia were isolated and examined to the extend of the inactivation of penicillins and the ability of 6-amino penicillanic acid (6-APA) production. Among them, 12 strains were found to produce penicillin acylase and to form 6-APA. The strain No. 11 of the isolates was selected to be the most excellent one producing the acylase. Optimum culture conditions for the production of the acylase of the strain were found as follows : pH at 7.6~8.0, time on 18 hrs, temperature at 34 to 38$^{\circ}C$. And effective levels of the medium were found to be contained 0.3% phenylacetic acid, 1.0％ yeast extract, 1.0％ peptone and 0.3％ L-glutamate. And, the production of the acylase by the isolate was strongly inhibited by 1% glycerol and the growth was remarkably retarded by the addition of 1.0% n-butylacetate. The acylase was extracted from the isolate and the crude enzyme of the acylase was prepared and the characteristies of the enzyme were primary examined in optimum pH, temperature, stabilities and reaction time.