• Journal of the Korean Chemical Society
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• v.17 no.5
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• pp.371-377
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• 1973

The low temperature anionic copolymerization of p-tolylisocyanate ($M_1$) with n-hexylisocyanate ($M_2$) in DMF was carried out with NaCN. Copolymers were characterized by osmometry and I. R. spectrophotometry. Also copolymer composition was analyzed by spectral measurements. The behavior of this copolymerization system was the type of less ideal, that is the $M_2$ prefers to react exclusively with the same kind of species. The stress-strain behavior of the copolymer obtained from equimolar comonomer feed exhibited somewhat brittle or rigid character.

• Macromolecular Research
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• v.16 no.7
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• pp.659-662
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• 2008

A new and useful poly(ethylene oxide)-based pH-sensitive block copolymer is introduced. Poly(ethylene oxide-b-N-phenylmaleimide) was first synthesized by anionic polymerization of N-phenylmaleimide (N-PMI) using mixed alkali metal polymeric alkoxide by sequential monomer addition method in the mixture of benzene/THF/DMSO (10/5/3, v/v/v) at room temperature. Reductive deimidation of the resulting block copolymer was performed using hydrazine monohydrate leading to the formation of the corresponding pH-sensitive poly(ethylene oxide-b-maleic acid).

• Korean Membrane Journal
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• v.10 no.1
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• pp.39-45
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• 2008

Polyelectrolyte complex based on two anionic polysaccharides, composed of sodium alginate and carrageenan, were prepared by interacting with divalent calcium ions in solution. The effects of annealing on the structural deformation of polyelectrolyte complex and on their characteristics at removing water from a methanol mixture from the point of molecular sieve were investigated and discussed. The result showed that the structural deformation of the annealed polyelectrolyte complex has an effect on the free volume between these polymer chains and the chelate segments such a shrinking of the overall morphology, which act as a molecular sieve in the separation of methanol and water mixtures.

• Journal of the Korean Applied Science and Technology
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• v.15 no.1
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• pp.63-78
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• 1998

A series of long chain N-acyl amino acid type anionic surfactants were prepared by treating fatty acid chlorides with three kinds of amino acids, that is, sodium N-acyl-sarcosinates, sodium N-acyl-N-methyl-${\beta}$-alaninates and sodium N-acyl-N-methyl-taurates in an alkaline solution. All prepared biodegradable surfactants were purified by thin layer chromatography and column chromatography, and identified their structures by spectral analysis.

• Proceedings of the Korean Society of Rheology Conference
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• 2002.05a
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• pp.25-27
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• 2002

In this study we investigated the reaction kinetics by a convenient but useful method-rheology to characterize the interface between two immiscible blends with a Reactive compatibilizer. Also, we made an attempt to correlate changes of interface roughness with rheological properties. The blend systems employed in this study was mono-carboxylated polystyrene (PS-mCOOH) and an poly(methyl methacrylate-ran-glycidylmethacrylate) (PMMA-GMA). PS-mCOOH was synthesized by an anionic polymerization and PMMA-GMA by a free radical polymerization. We prepared two plates of each polymer using compression molding with a smooth surface molder, then put one upon another. As soon as these two plates welds together inside a rheometer under nitrogen environment, the torque and moduli were obtained with reaction time at different temperatures. Through the analysis of this modulus change with reaction time, we estimated interfacial reaction and roughening. The increment of modulus in initial state can be correlated to the extent of reaction. We obtained the reaction kinetic constant by fitting appropriate kinetic equation into experimental data. We also showed that increment of modulus in later state was due to by roughened interface.

• Journal of Environmental Science International
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• v.7 no.2
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• pp.217-222
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• 1998

Organics matters including algae are the major contaminants of Nak-dong river and it's concentration Is more Increasing now. The use of coagulants has been Incresed for the effective treatment of drinking water, and aluminum coagulants have been the most widely used in raw water treatment. However, when inorganic metal coagulant is excessively used for long period, it would result in secondary problems, such as increasing sludge production, enhancing the cost of water treatment process, and increasing concentration of residual metal, especially aluminum. Therefore, recently. in order to reduce the use of metal coagulant and enhance the coagulation effectiveness, several alternative coagulants, such as polymeric Inorganic coagulants and organic polymers, have been used In water treatment plants. The objectives of thins research were (11 to determine optimum dosage concentration and compare the coajuiation efnciency at various pH ranees with alum alone, alum+cationic polymer, and alum+anlonlc polymer, (21 to evaluate the amount of alum reduced by using organic polymer, (31 to maximize removal officiency of organic matter and minimize the concentration of residual aluminum.

• Journal of Electrochemical Science and Technology
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• v.6 no.3
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• pp.88-94
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• 2015

In this study we investigated the electrocatalytic oxidation of saccharose on conductive polymer- Nickel oxide modified graphite electrodes based on the ability of anionic surfactants to form micelles in aqueous media. This NiO modified electrode showed higher electrocatalytic activity than Ni rode electrode in electrocatalytic oxidation of saccharose. The anodic peak currents show linear dependency with the square root of scan rate. This behavior is the characteristic of a diffusion controlled process. Under the CA regime the reaction followed a Cottrellian behavior and the diffusion coefficient of saccharose was found in agreement with the values obtained from CV measurements.

• Journal of the Korean Applied Science and Technology
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• v.27 no.1
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• pp.93-97
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• 2010

Silicone dioxide absorbed polyoxyethylene alkylether sulfate (EU-S75D) surfactant was prepared. The core-shell composite of inorganic/organic were polymerized by using styrene(St) as a shell monomer and potassium persulfate(KPS) as an initiator. We studied the effect of surfactants on the core-shell structure of silicone dioxide/styrene in the presence of an anionic surfactant lauryl sulfate(SLS). The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer(TGA) and morphology of latex by scanning electron microscope(SEM).

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.16-20
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• 2003

As the preliminary works for the preparation of exfoliated nanocomposites by reactive extrusion (REX) the modified anionic polymerization proceeded in a flask using an $\varepsilon$-caprolactam, catalyst, initiator, and clay. Polymerization methods were classified with a variation of the clay adding time. Intercalations mechanism of clay layers was investigated by measuring the WAXD peaks of clay with polymerization. In the preparation of nanocomposites, the molecular weight of nylon 6 was affected by the clay content. From the mechanical property measurement, improved properties were obtained in comparison to the neat nylon 6, and these properties were also affected by the molecular weight.

• Journal of Biomedical Engineering Research
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• v.9 no.1
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• pp.73-78
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• 1988

The polymer electrolyte complex hydrogels consisting of poly (methacrylic acid) and poly (4-vinylpyrridine) were formed and 5-flurouracil and pilocarpine drugs were loaded on their hydrogels. Cumulative 5-FU released from PEC hydrogel was affected by the degree of loading and release rate of 5-FU was followed by the monolithic type. Cumulative pilocarpine released from PEC hydrogel increased by ionic interaction between cationic pilocarpine and anionic PMA. Release rate showed the zero order after burst effect.