• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.474-478
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• 2018

For process safety, fire and explosion characteristics of combustible materials handled at industrial fields must be available. The combustion properties for the prevention of the accidents in the work place are flash point, fire point, explosion limit, and autoignition temperature (AIT) etc.. However, the combustion properties suggested in the Material Safety Data Sheet (MSDS) are presented differently according to the literatures. The accurate combustion properties are necessary to safely treatment, transportation and handling of flammable substances. In the chemical industries, n-ethylaniline which is widely used as a raw material of intermediate products and rubber chemicals was selected. For safe handling of n-ethyl aniline, the flash point, the fire point and the AIT were measured. The lower explosion limit (LEL)of n-ethylaniline was calculated using the lower flash point obtained in the experiment. The flash points of n- ethylaniline by using the Setaflash and Pensky-Martens closed-cup testers measured $77^{\circ}C$ and $82^{\circ}C$, respectively. The flash points of n-ethylaniline using the Tag and Cleveland open cup testers are measured $85^{\circ}C$ and $92^{\circ}C$, respectively. The AIT of the measured n-ethyl aniline by the ASTM E659 apparatus was measured at $396^{\circ}C$. The LEL of n-ethylaniline measured by Setaflash closed-cup tester at $77^{\circ}C$ was calculated to be 1.02 vol%. In this study, it was possible to predict the LEL by using the lower flash point of n-ethylaniline measured by closed-cup tester. The relationship between the ignition temperature and the ignition delay time of the n-ethylaniline proposed in this study makes it possible to predict the ignition delay time at different ignition temperatures.

• Textile Coloration and Finishing
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• v.33 no.2
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• pp.49-63
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• 2021

In this study, a convenient approach for sensitive, quick and simple detection of hazardous acids was investigated. A series of azo dyes were synthesized and applied as a chemosensor for the acid detection both on fibers and in solution. Various aniline, benzothiazole or isoxazole derivatives were used as diazo component and coupled with N-benzyl-N-ethylaniline or 2,2'-(phenylimino)bis-ethanol to give azo based dyes. The acid sensing phenomenon was observed by naked-eye and detection was further confirmed by UV-Vis spectrophotometer and hue difference(ΔH^*) evaluation. The developed sensors showed a distinct and quick color change from yellow to magenta by addition of trace amounts of the hazardous acids. The absorption maxima was shifted to a longer wavelength by 70 ~ 150nm and hue difference(ΔH^*) was 60 ~ 120°. A cotton fiber coated with Dye 1 exhibited excellent storage stability under various temperature(-30 ~ 43℃) and humidity(30 ~ 80%) conditions without discoloration and fading of the fiber sensors. Also the acid sensing properties were maintained.

• Journal of the Korean Chemical Society
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• v.15 no.6
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• pp.312-317
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• 1971

The interactions of aniline, o-toluidine, o-ethylaniline and o-chloroaniline with iodine in carbon tetrachloride solution have been examined through spectrophotometric measurements. The results indicate that both aniline and the o-substituted anilines examined form one-to-one complexes with I2in solution. The formation constants of the complexes measured at room temperature are 12.8, 9.31, 3.15 and 0.576 l $mole^{-1}$, respectively. Comparison of these results with previous experimental results indicates that the relative stabilities of the $I_2$-amine complexes decrease in the following order: $C_6H_5N(C_2H_5)_2 >C_6H_5N(CH_3)_2 >C_6H_5NH_2 >o-CH_3C_6H_4NH_2 >o-C_2H_5C_6H_4NH_2 >o-ClC_6H_4NH_2$. This may support the conclusion that the relative stabilities of these complexes are explained by the inductive effect and steric hindrance of the substituents.