• Applied Chemistry for Engineering
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• v.4 no.1
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• pp.132-143
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• 1993

Aminomethyl polystyrene resins were prepared either from chloromethyl-resin(Merrifield resin) or from direct amidoalkylation of polystyrene resin. Two kinds of aminomethlyl resin were lengthened with spacer arms via sequential coupling of five ${\varepsilon}$-aminocaproic acids(ACA) respectively. In case of the resin prepared from the Merrifield resin, the amounts of free amino group of the resin were reduced by 25~30% after each coupling of ACA. But the one from direct amidoalkylation showed 3~5% loss after each coupling of ACA. 4-Nitroso-5-aminopyrazole resin was made by reacting ACA spacer arm resin, which was made from direct amidoalkylated resin, with 5-phenyl-7-methylpyrazole [4,3-c][1,2,4]oxadiazin-3-one. Several polymeric active esters of N-blocked amino acids were prepared from the 4-nitroso-5-aminopyrazole bound resins. In anchoring step of the amino acid derivatives on the resin, no substantial effect of bulkiness was found. 4-Nitroso-5-aminopyrazole bound active ester resins were found to be very reactive in N-acylation, The resulting peptides were obtained with 90~95% yield and characterized by NMR and other physical methods.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.10a
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• pp.237-240
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• 2002

Amino terminated polyetherimide(ATPEI) has been synthesized by bisphthalic anhydride arid m-phenylenediamine, after that characterized by differential scanning calorimetry(DSC), thermogravimetric analyzer(TGA). Fourier transform (FT-IR) spectroscopy and gel permeation chromatography(GPC). ATPEI was blend to improve the toughness of bisphenol-A type epoxy resin which was cured by nadic methyl anhydride(NMA). The fracture toughness and the molphology of the toughened epoxy resin was evaluated. The toughness of ATPEI modified epoxy resin was higher than that of the PEI modified epoxy resin. In addtion, carbon fiber/ATPEI modified epoxy resin composites were fabricated and the mechanical properties of the resulted composites were investigated.

• Bulletin of the Korean Chemical Society
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• v.35 no.8
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• pp.2381-2384
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• 2014

A solid-phase synthetic approach is reported for the synthesis of an ascorbic acid (ASA)-dipeptide conjugate that exhibited enhanced antioxidant activity. The N-terminal amino group of dipeptide (Ala-Ala) on a resin support was first activated by 1,1'-carbonyldiimidazole (CDI), and then reacted with an ASA derivative. The addition of a base, triethylamine (TEA), promoted nucleophilic acylation of ASA derivative and yielded a desired product (ASA-Ala-Ala) with enhanced purity, when cleaved from the resin. Compared to the approach where a C3 hydroxyl group of ASA was first activated with CDI and then reacted with the amino group of dipeptide on the resin, this new approach allowed a significant reduction of a total reaction time from 120 h to 8 h at $25^{\circ}C$. As-prepared ASA-dipeptide conjugate (ASA-Ala-Ala) showed improved antioxidant activity compared to ASA.

• YAKHAK HOEJI
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• v.8 no.2
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• pp.48-53
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• 1964

At the different growing stages of Fagopyrum esculentum Moench planted at the green house and out doors, the contents of free amino acids in the whole plants,were determined quantitatively by spot-extract colorimetric method (J. Awapara method) using the chromatograms obtained by the ion-exchange resin and paper chromatographic method. And the contents of carbohydrate in the whole plant were determined by Bertrand method. The results were summarized as follows. 1. Almost same kinds of free amino acids were detected in the both plants. 2. Concentrations of most amino acids was increased progressively during growth; further growth was accompanied by decreased concentrations. 3. Rate of growth and increasing of total amino acid content of green house plant is greater than that of out dorrs plant. 4. At the same stages of gwoth, total free amino acid content of green house plant is higher than that of out doors plant but sugar content is lower. 5. There was rapidly increasing of sugar content and decreasing of total free amino acid content except asparagine during mature of seeds.

• Journal of the Korean Applied Science and Technology
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• v.26 no.1
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• pp.18-23
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• 2009

Curing behavior and structural property of an inorganic compound added urea-formaldehyde(UF) and urea-melamine-formaldehyde(UMF) were studied. In addition, tensile strength and formaldehyde emission of plywoods made of those resin binders were studied. Curing temperature and structure were not changed, but tensile strengths of plywoods manufactured both with a UF resin and a UMF resin were decreased slightly as increased amount of inorganic compound. Formaldehyde emissions from plywoods were reduced as increased amount of inorganic compound. Wheat flour as an extender was helped to reduce of formaldehyde emission. From the result of this study it might be estimated that using appropriate amount of inorganic compound and proper resin system can be strengthened bond strength and reduced formaldehyde emission.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.147-150
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• 2002

The cure kinetics of blends of epoxy (DGEBA:diglycidyl ether of bisphenol A)/anhydride (NMA:nadic methyl anhydride) resin with synthesized amino terminated polyetherimide (AT-PEI) were studied using differential scanning calorimetry (DSC) and Dynamic Mechanical Analysizer(DMA) under isothermal condition to determine the reaction parameters and gel-vitrification behavior. The fracture toughness of AT-PEI 20phr/epoxy resin system was improved over 224% and 42.5% more than neat epoxy resin and commercial PEI/Epoxy Resin System.

• Journal of Pharmaceutical Investigation
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• v.19 no.3
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• pp.117-121
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• 1989

A metal complex, copper (II) L-proline was chemically bound to ethylene glycol dimethacrylate and divinylbenzene crosslinked chloromethylated polystyrene and they were used as chiral chelate resin matrix for column chromatography to resolve enantiomers of DL-amino acids. The L-enantiomers eluted first and the degree of resolution on the polymer crosslinked with ethylene glycol dimethacrylate was superior to the polymer crosslinked with divinylbenzene.

• Journal of the Korean Chemical Society
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• v.7 no.1
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• pp.6-12
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• 1963

Amino acid composition of Makjang was determined by combined usage of ion exchanged resin and paper chormatography in the following states. a. A fraction soluble in water b. Hydrolysate of the whole Makjang c. Same as a. (p.p.t. formed by tungstic acid or trichloroacetic acid being removed) d. Hydrolysate of c. (T and TCA) By comparing amino acid composition of Makjang with that of its raw material, we found that decomposition of essential amino acids during brewing is slight. From the amino acid composition of a,b,c,d, we discussed the ratio of amino acid liberation during brewing and assumed that Makjang contains peptide-like substances composing of glutamic acid and aspartic acid.

• Environmental Analysis Health and Toxicology
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• v.1 no.1
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• pp.77-80
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• 1986

Radiochemical synthesis of $N^{G}$-mono［$^{14}$ C-methyl］-L-arginine is described. The compound was synthesized from radio-active mono［$^{14}$ C］-methylamine as easily and purified by strong cation-exchange resin (NH form) liquid chromatography using a gradient of ammonium hydroxide, and crystallized as flavianate. The free amino acid was successfully prepared by strirring its flavianate and strong anion-exchange resin (OH- form), which could remove the flavianic acid from its salt in water below room temperature. Purity of the compound was tested by thin-layer chromatography, thin-layer electro-phoresis, and scintillation spectrometry.y.

• Applied Chemistry for Engineering
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• v.4 no.4
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• pp.823-829
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• 1993

The basic medium oil modified alkyd resin was synthesized from linseed oil fatty acid(LOFA), phthalic anhydride(PAA), trimellitic anhydride(TMA ), and trimthylol propane(TMP) by condensation polymerization at $230^{\circ}C$. TMPTA modified water-reducible alkyd resins were synthesized with TMPTA graft copolymerization onto the basic resin at $180^{\circ}C$. Acid value of the resin was controlled by the addition of TMA and N,N-Dimethylethanol amino(DMEA) was used as an neutralizing agent to prepare water-reducible alkyd. To evaluate the optimum formulation for anionic alkyd resin, water proofness and water reducibility were estimated from the acid value or TMA contents. The effect of TMPTA on the graft copoymerization of the resin was studied by measuring molecular weight, glass transition temperature(Tg), viscosity, and gel contents. The suitable balance of water proofness and water reducibility of the resin was obtained at range of 5.3~7.0wt.% of TMA contents or 40~50 of acid value of basic resin. The molecular weight, viscosity, and gel contents of water-reducible alkyd resin were increased according to the TMPTA graft copolymerization, but Tg was decreased.