• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.18-27
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• 2002

Pine bark was liquefied in the presence of phenol using organic sulfonic acids as catalysts, and the liquefied barks were characterized. It was found that the organic sulfonic acids were more effective catalysts than hydrochloric acid for complete liquefaction of pine bark. The liquefied barks prepared from phenol-organic sulfonic acid liquefaction were highly phenolated, and the amounts of combined phenol were 2-3 times greater than that of the liquefied bark obtained from phenol-hydrochloric acid liquefaction. The glass transition points (Tg) were lower than that of the liquefied barks prepared from phenol-hydrochloric acid. It can be concluded that by using the organic sulfonic acids, the phenol used as a liquefying reagent is highly introduced into the bark, resulting in the phenolated bark preventing further condensation reactions, which may occur during the liquefaction. The carbohydrates such as cellulose and hemicellulose in the liquefied barks were almost decomposed during the liquefaction, from the results of IR spectra and neutral sugar analyses. Energy dispersive X-ray spectromery (EDS) results from the residues and the liquefied barks showed that the organic sulfonic acid catalysts did not lead to serious corrosion of the reactor compared with the hydrochloric acid catalyst.

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.1-9
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• 2002

Various types of acids, such as mineral acids, organic acids, and organic sulfonic acids, were used as catalysts in order to investigate their effectiveness during phenol liquefaction of pine bark. Hydrochloric arid was the most effective acid catalyst of the mineral acids used in this experiment for the phenol liquefaction, but the amount of the acid needed for more than 90% liquefaction was at least 11 mmol. Among the carboxylic acids used triflouroacetic acid (TFA) was effective for the liquefaction, but it was not possible to obtain liquefaction of more than 80%. Organic sulfonic acids, p-toluenesulfonic acid (PTSA) and methanesulfonic acid (MSA), showed remarkable effects for liquefaction, even in small amounts and at low liquefaction temperatures. Especially in the case of PTSA, a 92% liquefaction yield was obtained at the liquefaction condition of 14$0^{\circ}C$ for 2 h. Therefore, it was evident that the PTSA is a good acid catalyst for the phenol-pine bark liquefaction system.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2006.11a
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• pp.44-46
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• 2006

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.787-792
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• 2011

Under mild conditions and without any additional organic solvent, synthesis of carbamatoalkyl naphthols could be carried out in the present of two halogen-free Br${\phi}$nsted acidic ionic liquids, 3-methyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate and N-(4-sulfonic acid)butylpyridinium hydrogen sulfate. A wide range of aromatic aldehydes easily undergo condensation with $\beta$-naphthol and methyl or benzyl carbamate to afford the desired products of good purity in excellent yields. The present methodology offers several advantages such as a simple procedure with an easy work-up, short reaction times, and excellent yields. The catalysts could be recycled and reused for several times without substantial reduction in their catalytic activities.

• Proceedings of the Membrane Society of Korea Conference
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• 1994.04a
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• pp.55-56
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• 1994

There has been many attempts to improve the membrane performance using pervaporation processes[l-3]. They are 1) blending polymer with the high flux and one with high selectivity, 2) an incorporation of functional groups interacting with permeants into a membrane through copolymerization or modification, 3) composite membrane or asymmetric membrane structure with a thin skin layer which acts as a selective layer. Among them, a polymeric membrane containing ion complex group receives an extensive attention recently because ionic complex is known to activate the water transport through ion-dipole interaction. It is especially advantageous in the separation of organic-water system. We applied the ideas of the activation of water transport through ion-dipole. We have reported on the in-sire complex membrane to separate water from aqueous aceiic acid and pyridme solution[4-5] based on the simple acid-base theory. Water transport was enhanced through in-situ complex between pyridine moiety in the membrane and the incoming acetic acid in the feed. In this case, catalytic transport mechanism was proposed. In the present study we used pyridine solution as a feed and the sulfonic acid group in the membrane.

• Journal of the Korean Chemical Society
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• v.36 no.1
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• pp.125-130
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• 1992

Stereoisomers of trifluoroethylmandelate(mandelic acid trifluoroethylester) were synthesized from each isomer of mandelic acid and trifluoroethanol with p-toluene sulfonic acid in order to study the enantioselectivity of lipase in organic solvent. The products were identified by $^1H$ NMR and elemental analysis and their physical properties such as melting point, densities and specific optical rotations($[{\alpha}]_{25}{^D}$) were also characterized. $[{\alpha}]_{25}{^D}$ of (+)- and (-)-trifluoroethylmandelate were +74° and -75.4°, respectively. The trifluoroethylmandelate was found out to be as a good substrate for the transesterfication stereoselectivity of lipases in organic solvent. Any significant difference of the lipase catalyzed transesterification activity between (+)- and (-)-methylchloropropionate was not found, and even lipase activity of transesterfication was not found with high optical polar (+)-and (-)-methylmandelate.

• Clean Technology
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• v.30 no.2
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• pp.105-112
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• 2024

Globally, the demand for electric vehicles has surged due to greenhouse gas regulations related to climate change, leading to an increase in the production of used batteries as a consequence of the battery life issue. This study aims to selectively leach and recover valuable metal lithium from the cathode material of spent LFP (LiFePO₄) batteries among lithium-ion batteries. Generally, the use of inorganic acids results in the emission of toxic gases or the generation of large quantities of wastewater, causing environmental issues. To address this, research is being conducted to leach lithium using organic acids and other leaching agents. In this study, selective leaching was performed using the organic acid methane sulfonic acid (MSA, CH₃SO₃H). Experiments were conducted to determine the optimal conditions for selectively leaching lithium by varying the MSA concentration, pulp density, and hydrogen peroxide dosage. The results of this study showed that lithium was leached at approximately 100%, while iron and phosphorus components were leached at about 1%, verifying the leaching efficiency and the leaching rates of the main components under different variables.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.666-671
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• 1999

In this work, sulfonated poly(phenylene sulfide) (SPPS) was prepared by demethylation with aqueous NaOH solution after poly[methyl[4-(phenylthio)phenyl]sulfonium trifluoromethanesulfonate](PPST) was sulfonated with fumic sulfonic acid(10% $SO_{3}-H_{2}SO_{4}$). PPST soluble in organic solvents was synthesiszed by self-condensation polymerization of methyl-(phenylthio)phenyl sulfoxide(MPPSO). SPPS showed IR bands of asymmetric O=S=O stretching at $1200cm^{-1}$ and S-O stretching at $621cm^{-1}$ from $-SO_{3}H$ group. From the result, it could be known that sulfonic acid groups were introduced to poly(phenylene sulfide). when PPST was sulfonated for 12hr at $150^{\circ}C$, 1.48 sulfonic acid groups were introduced per repeat unit. The weight average molecular weight(Mw) of PPST and SPPS determined by high temperature GPC were 118323 and 131204, respectively. The SPPS exhibited adsorption capacity of ammonia gas $9.67mmol\;NH_{3}/g$ and it was much higher than that of active carbon or silica gel.

• Bulletin of the Korean Chemical Society
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• v.16 no.5
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• pp.416-421
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• 1995

The approximate rates and stoichiometry of the reaction of excess lithium gallium hydride with selected organic compounds containing representative functional groups were examined under the standard conditions (diethyl ether, 0 $^{\circ}C)$ in order to compare its reducing characteristics with lithium aluminum hydride and lithium borohydride previously reported, and enlarge the scope of its applicability as a reducing agent. Alcohols, phenol, and amines evolve hydrogen rapidly and quantitatively. However lithium gallium hydride reacts with only one active hydrogen of primary amine. Aldehydes and ketones of diverse structure are rapidly reduced to the corresponding alcohols. Conjugated aldehyde and ketone such as cinnamaldehyde and methyl vinyl ketone are rapidly reduced to the corresponding saturated alcohols. p-Benzoquinone is mainly reduces to hydroquinone. Caproic acid and benzoic acid liberate hydrogen rapidly and quantitatively, but reduction proceeds slowly. The acid chlorides and esters tested are all rapidly reduced to the corresponding alcohols. Alkyl halides and epoxides are reduced rapidly with an uptake of 1 equiv of hydride. Styrene oxide is reduced to give 1-phenylethanol quantitatively. Primary amides are reduced slowly. Benzonitrile consumes 2.0 equiv of hydride rapidly, whereas capronitrile is reduced slowly. Nitro compounds consumed 2.9 equiv of hydride, of which 1.9 equiv is for reduction, whereas azobenzene, and azoxybenzene are inert toward this reagent. Cyclohexanone oxime is reduced consuming 2.0 equiv of hydride for reduction at a moderate rate. Pyridine is inert toward this reagent. Disulfides and sulfoxides are reduced slowly, whereas sulfide, sulfone, and sulfonate are inert under these reaction conditions. Sulfonic acid evolves 1 equiv of hydrogen instantly, but reduction is not proceeded.

• Textile Coloration and Finishing
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• v.24 no.4
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• pp.239-246
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• 2012

The binding isotherms of ionic dyes with Poly(vinylpyrrolidone) in aqueous solution were determined by the dynamic dialysis technique. The shape of the isotherms of cationic dye, C. I. Basic Red 18 with poly(vinlypyrrolidone) showed a partition type. It suggests that the binding involves a non-cooperative mode. Isotherms of an anion dye, a synthesized dye by coupling of diazotized m-trifluoromethylaniline with 2-naphthol-6-sulfonic acid, were sigmoid type and showed multimode interaction. The results were interpreted by the McGhee von Hippel theory. The thermodynamic parameters for the complex formation of the dyes-polymer were calculated from their temperature dependences of the intrinsic binding constant.