• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.1046-1050
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• 2004

Six physical properties (enthalpy, density, decomposition temperature, solubility in water, pKa values, and hydronium potential) were examined by molecular modeling techniques. The molecular connectivity index, Wiener distance index, and Ad hoc descriptor are employed as structural parameters to encode information about branching, size, cyclization, unsaturation, heteroatom content, and polarizability. This paper examines the correlation of the molecular modeling techniques parameters and the physicochemical properties of amino acids. As a results, calculated values were in agreement with experimental data in the above six physical properties of amino acids and the molecular connectivity index was superior to the other indices in fitting the calculated data.

• Journal of the Korean Applied Science and Technology
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• v.28 no.4
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• pp.438-448
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• 2011

Chitosan is widely used in cosmetics and medical fields. Special emphasis has been put on the chemical modification of chitosan to explore its full potential. We have described the synthesis and biological activity of novel peptide amino acid derivatives. The polyamino acid derivatives were synthesized by introducing alkylamine functional group on chitosan at C-6. The poor aqueous solubility of chitosan derivatives hinder both pharmacological studies and pharmaceutical development. To make amino acid coupled chitosan derivatives with improved biological effect and solubility, some attempts have been taken to consist of amino peptide group like aspartic acid and phenylalanine-aspartic acid derivatives onto chitosan C-6. The resultingly substituted chitosan was characterized by solubility in various solvents. We measured chitosan derivatives with $^1H$-NMR and $^{13}C$-NMR. Also, We were investigated on the physical properties and biological activities of these products.

• Journal of the Korean Chemical Society
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• v.15 no.1
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• pp.15-22
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• 1971

DL-1-Amino-pentyl phosphonic acid, DL-1-Aminopropyl phosphonic acid were synthesized with good yield from caproic acid and butyric acid using the modified Curtius reaction and N-derivatives, N-acetyl-DL-1-amino propyl phosphonic acid, N-acetyl-DL-1-aminopentyl phosphonic acid, N-Benzoyl-DL-1-amino-propyl phosphonic acid, were also prepared by a variety of methods including the Schotten-Baumann reaction. In addition, the chemical and physical properties of the products were investigated. All the products were also identified by means of elemental analysis, Infrared spectrophotometry, Ninhydrin test, and the determination of the neuralization equivalent.

• Journal of the Korean Applied Science and Technology
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• v.17 no.2
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• pp.99-104
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• 2000

Physical properties and performance characteristics of sodium salt of several pure N-acyl amino acids made from glycine, dl-alanine, sarcosine, dl-valine, l-leucine, l-aspartic acid and l-lysine seven long chain fatty acids are reported. The effect of acyl chain length and the differences in the structure of constituent amino acid of seven homologous series of amide intermediate linked carboxylate surfactant of this class on the properties are discussed.

• Journal of Fashion Business
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• v.13 no.1
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• pp.102-114
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• 2009

Chitosan is a polysaccharide with cationic amino groups in its structure and has useful properties as functional materials. Various end-use developments of chitosan are in progress. When the cotton fabric is pretreated with chitosan, the hand property of cotton fabric may be improved expecially for the summer apparel. In this study, as a cross-linking agent to introduce chitosan into cotton, BTCA(butane-1,2,3,4-tetracarboxylic acid) or CA(citric acid) was added in order to prevent detachment of chitosan by the cross-linking. During the cross-linking procedure, via the padding-drying-heat setting, amino groups of chitosan and hydroxyl groups of cotton, carboxyl groups of BTCA/CA are cross-linked by forming anhydrous cyclic rings. Since BTCA has four carboxyl groups, cross-linking by thermal treatment is easy, leading to the trials in wrinkle-recovery treatment of cotton fabrics. However, the high price of the BTCA reagent has been a shortcoming in the actual application for industrial use. Therefore, in this study, we tried the application of CA having three carboxyl groups, which is relatively low priced, as the substituting cross-linking agent. The hand of the treated fabrics were evaluated by measuring physical properties. In addition, based on the physical properties, three-dimensional images were introduced by using 3D CAD systems and results were compared.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2131-2137
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• 2013

In this work, the key intermediate, 4-amino-4'-(2-amino-4-anilino-1,3,5-triazine-6-yl)-aminostilbene-2,2'-disulfonic acid, was prepared from 4-(2-amino-4-anilino-1,3,5-triazine-6-yl)amino-4'-nitrostilbene-2,2'-disulfonate by using Tin(II) chloride as the reducing agent. Using this intermediate, nineteen new asymmetrically substituted bistriazinylstilbene fluorescent brightening agents were synthesized. Chemical structures of the obtained compounds 5a-s were analyzed by proton NMR spectrum. The physical properties of the new compounds 5a-s were characterized by fastness test and whiteness measurement test and the obtained data were compared to measurements obtained from CI 86.

• Textile Coloration and Finishing
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• v.16 no.4
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• pp.1-9
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• 2004

In recent, development of nano fiber has been one of the most active subjects in the world. Nano fiber is defined as a ultra fine yarn with a diameter unit of $10-100\times10^{-9}meter$, which is possible to be produced by an electro-spinning technology. In this study, physical characteristics and dyeing properties of nylon 66 nano fiber were investigated. Nylon 66 nano fiber was dyed with levelling type acid dyes. X-ray diffraction method and DSC analysis were used for the measurement of the degree of crystallization. Analysis of amino end groups was also performed in order to examine a relationship between number of amino groups and its dyeing property as well as water absorption behavior. The maximum exhaustion % of dyes and dyeing rate under various dyeing conditions, such as dyeing temperature and pH in dye bath, along with build-up properties for 2 acid dyes were evaluated. It was found that the degree of crystallization of nano fiber was smaller than that of regular fiber, and amino end groups of nano fiber were less than regular fiber. Half dyeing time of nano fiber was shorter than regular fiber because of the bigger specific surface area. Effect of pH on exhaustion % was small in case of nano fiber. Exhaustion of nano fiber increased with higher concentration of dye.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.49-53
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• 1996

This experiment was carried out to study the effect of oxygen on chemical composition and physical properties of tobacco leaves during flue-curing. The results obtained were as follows: Starch content decreased and sucrose content increased with increasing oxygen supply during curing. Glucose and fructose of the cured leaves showed high content at the 5-10% oxygen supply. Amino-N and nitrate-N increased with increasing oxygen supply. Total nitrogen and NH4-N showed the lowest value at the 5-10% and 10-15% oxygen supply in the cutters and leaf, respectively. Chlorophyll and chlorogenic acid increased, and total volatile base decreased with increasing oxygen supply. The activity of α-amylase increased at the latter period of flue-curing, and the maximum activity point were delayed 12 hours with increasing oxygen supply. Shatter index of cured leaves decreased with increasing oxygen supply. It was desirable to supply oxygen during flue-curing for the improvement of chemical and physical properties such as starch, total sugar, chlorogenic acid, and shatter index of cured leaves.

• Textile Coloration and Finishing
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• v.17 no.1
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• pp.52-59
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• 2005

The purpose of this study is to establish the scientific data of cotton fabric pretreated with skim milk powder and to improve the dyeability. The surface monophology, add on, whiteness, stiffness, air permeability, moisture regain and absorption of cotton fabrics were evaluated by varying concentration of SMP to get the optimal conditions in pretreatment. FT-IR of cotton fabrics pretreated with SMP were measured. Amino acid compositions, viscosity of SMP were evaluated. The K/S values by varying concentration of cinnamon cassia and subtract of dyed SMP-C were measured. I attempted to evalute the color fastness of untreated and AI. The results are as follow; The optimal concentration of SMP was 9%(w/v) to be pretreated with cotton fabrics. From FT-IR spectrum, formation of -NH$_2$ and -COOH was verified by SMP-C. Denaturalization of protein and condensation of carbohydrate, fat, etc. were found in a measurement of amino acid and viscocity. The K/S value of cotton fabrics pretreated with SMP was higher than that of untreated. Most of the color fastnesses were great.

• Fibers and Polymers
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• v.6 no.1
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• pp.35-41
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• 2005

Research and development of nano fiber products is very active over the world. Physical characteristics and dyeing properties of nylon 66 nano fiber were investigated in this study. X-ray diffraction, DSC, analysis of amino end group, and water absorption were performed to get information concerning physical properties of nano fiber. Nylon 66 nano fiber was dyed with high molecular mass acid dyes. Effects of dyeing temperature, pH of dyeing solution, and concentration of acid dyes on dyeing properties such as rate of dyeing and the extent of exhaustion, were examined and compared to those of regu­lar fiber. It was found that nano fiber adsorbed acid dyes at lower temperature, got rapidly dyed, and its extents of exhaustion at specific dyeing temperature were higher than regular fiber. It was also observed that nano fiber could adsorb a large amount of acid dye without a significant loss in the extent of exhaustion. Washing fastness of the dyed nano fiber was lower by $1/2\~1$ grade, light fastness by 1 grade than the dyed regular fiber.