• Applied Chemistry for Engineering
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• v.24 no.6
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• pp.650-655
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• 2013

In this study, the synthesis of succinic acid from hydrogenation of maleic anhydride over Pd/C were performed in aqueous solution at various reaction conditions. We confirmed that the distribution of product was different according to process parameters. When increasing the reaction pressure and agitation speed, the by-product decreased and the purity of succinic acid increased. From the result, we may conclude that the reaction pressure and agitation speed are important factors for promoting the mass transfer rate of gas-liquid interface by increasing gas-liquid solubility in liquid hydrogenation. When the reaction pressure increased from 5 bar to 10 bar, the reaction rate increased 2.14 times. When the agitation speed increased from 300 rpm to 700 rpm, the reaction rate increased 2.75 times.

• The Korean Journal of Mycology
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• v.17 no.3
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• pp.105-113
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• 1989

For selective purification of proteins in Pleurotus cornucopiae, affinity chromatography was performed by p-aminoanilinylsuccinyl-AH-Sepharose 4B gel synthesized by treating p-phenylene diamine with succinyl-AH-Sepharose 4B, which was prepared by treating AH-Sepharose 4B with succinic anhydride. The capacity of p-aminoanilinyl ligand group was 6.1 micromole per milliliter of gel. Total apparent molecular weight of the affinity proteins eluted from the synthesized gel was 167 KD, which were a protein complex of 130 KD and 37 KD. The contents of the nonpolar, polar, positively and/or negatively charged amino acids in the affinity protein were 44.57%, 24.75%, 21.25%, and 9.43%, respectively. Total apparent molecular weight of the affinity proteins eluted from the AH-Sepharose 4B gel was 95.2 KD, which were a protein complex of 61 KD, 31 KD and 3.2 KD. The contents of the nonpolar, positively and/or negatively charged amino acids in the affinity protein by AH-Sepharose 4B gel were 44.05%, 29.13%, and 12.91% respectively.

• Textile Coloration and Finishing
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• v.8 no.2
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• pp.64-70
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• 1996

Wool yarns were treated in dimethylformamide solutions containing various concntrations of three dibasic acid anhydrides: succinic, itaconic, and phthalic arthydrides in various conditions. The structurl aspects of these dibasic acid anhydries are different: succinic, itaconic, and phthalic acid arthydrides have saturated aliphatic ethylene, unsaturated aliphatic vinyl and aromatic phenyl one groups, respectively. The properties of acylated wool keratin are as follows: Decreasing amino group and increasing carboxyl group by acylation lowered the hydrophilic property, and then moisture regain, and decreased acid dye uptake and enhanced cationic dye uptake of wool keratin. In the case of phthalic acid anhydries, in spite of lowest acyl content, the minimum of moisture regain was resulted from the bulk benzen ring, occuping much more voids on wool keratin molecules than other reagents. Acid solubility was increased by the decrease of amino group and hydrogen bonding by acylation. Alkali solubility was also increased formation of new amide group on the side chain of keratin, which can be degraded easily by alkali. In the case of phthalic acid anhydride, the relative high solubility was resulted from the much higher molecular weight of dissolved fractions. The surface of wool keratin was not damaged by treatment with any acylating agent.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.313-320
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• 1994

Rosin-maleic anhydride adduct(RMA) was synthesized from rosin and maleic anhydride. Highly purified RMA for the application of polymerization monomer was synthesized by means of two methods; the melt reaction followed by further purification and the solution reaction. As a result of this study, the solution reaction was better than the melt reaction for obtaining higher yield of RMA. Maximum yield of RMA obtained by the melt reaction was only 40%. But the yield of RMA obtained by the reaction in carbon tetrachloride solution was 48%(theoretical yield 87.6%) and that obtained by the reaction in acetic acid solution was 51.5%(theoretical yield 94%) respectively.

• Applied Chemistry for Engineering
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• v.24 no.3
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• pp.320-326
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• 2013

In this study, various polyimide films were synthesized via low temperature cure in order to understand changes in their physical properties when using 4,4'-oxydianiline (ODA) as a diamine and dianhydride molecules with different backbones on a single diamine such as 4,4'-Oxydiphthalic anhydride (ODPA), 4,4-hexafluoroisopropylidene diphthalic dianhydride (6FDA), and 3,3', 4,4'-benzophenone tetracarboxylic dianhydride (BTDA). After the synthesis of poly(amic acid), polyimide films were fabricated by adding 1,4-diazabicyclo [2.2.2]octane (DABCO), a low-temperature catalyst, at various wt% to poly(amic acid)s. Changes of optical and thermal properties were compared and analyzed between polyimide films without catalyst and polyimide films with catalyst by FT-IR, UV-Vis transmittance, DSC/TGA, and WAXD analysis. Wide-angle X-ray diffraction (WAXD) analysis revealed that the mean intermolecular distance decreased with the use of a catalyst by the type of dianhydride. Thus, while the optical properties of the films improve by a low-temperature cure performed using a catalyst, their thermal properties decrease. These changes can be explained by the changes in the morphological structure of the films triggered by a catalyst-induced reduction in the mean intermolecular distance. Moreover, the results show that the type of dianhydride determines the degree of change in the optical and thermal properties in each types of polyimide, demonstrating that changes in the optical and thermal properties are directly associated with the backbone of the polyimide structure.

• Elastomers and Composites
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• v.38 no.3
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• pp.262-272
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• 2003

Maleic anhydride-grafted-polypropylene(PP-g-MA) were used as a blend component and a compatibilizer, respectively, for two reactive blends of polyamide 66(PA 66)PP-g-MA binary blends and PA 66/polypropylene(PP)/PP-g-MA ternary blends. The goal of this work was to investigate the property differences between binary and ternary blends. Tensile strength, flexural modulus, heat deflection temperature, impact strength, melt flow index, and the dependence of melt viscosity on the shear rate were examined. The impact strengths of binary blends were higher than those of ternary blends at all compositions, since the in situ synthesis of PP-g-PA 66 copolymer through the imide formation between the amine end group of PA 66 and the anhydride group of PP-g-MA gave the increase of molecular weight and was more popular in binary blends than in ternary blends. In case of ternary blends, most of the properties were superior to those of binary blends, owing to the better properties of PP compared with PP-g-MA. The toughened binary blends with 70/30(PA 66/PP-g-MA) and 80/20 ratios were not commercially applicable due to their poor processibility. So, the ternary blends which showed lower melt viscosities were recommended for the commercial applications.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.1
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• pp.50-57
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• 2016

We studied the Lab-scale process for the development of DNAM in aspect of safety and overall efficiency. Melamine is used for starting material of process, DNAM was synthesized by oxidation and nitration reaction. In order to optimize the process parameters with the product in higher yield and purity, a systematic study with variation of different parameters like molar ratio of nitrating mixture, conditioning time and order of reactant was carried out. The optimized reaction conditions for the synthesis of DNAM were : conditioning time of $3{\pm}3.5$ hour and nitrating mixture in 1:1.4 molar ratio. In order to proceed a stable reaction, melamine was added with enough time to relieve reaction heat. From these reaction condition, DNAM could be obtained in a yield of more than 60%.

• Korean Journal of Food Science and Technology
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• v.19 no.5
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• pp.430-434
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• 1987

Fatty acid fraction rich in ${\omega}-3$ polyunsaturated fatty acids (${\omega}-3$, PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) could be obtained by saponification of fish oil in ethanol containing alkali hydroxide followed by cooling and filtration of the resultant solution. Fatty acid compositions of fish oil and the concentrates suggest that the ratio of number of double bonds to carbon number in a fatty acid molecule is a more important factor than the degree of unsaturation or the chain length in determining the solubility of fatty acid salts in ethanol. Water content in ethano1 affected significantly the efficiency of the separation with respect to yield and content of EPA and DHA in the concentrates; the lower the water content, the higher the efficiency. It was, however, influenced little by cooling procedure and temperature which the saponified solution experienced during the crystallization. Under an optimal condition, the contents of EPA and DHA in the concentrate increased by 2.4 and 2.5 times, respectively, as compared with those in sardine oil.

• Polymer(Korea)
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• v.27 no.4
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• pp.392-395
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• 2003

Phosrhonium salt exchanged montmorillonites were prepared from a reaction between alkyl triphenyl phosponium bromide and Na$^{＋}$-montmorillonite. Epoxy-clay nanocomposites were also prepared by using cycloaliphtic epoxy, methyl tetrahydrophthalic anhydride as a hardener, and triphenyl butyl phosphonium bromide as an accelerator. TEM and XRD results suggested that clay minerals in the epoxy-montmorillonites composite were intercalated. Mechanical properties such as tensile modulus and strength were measured and the effect of nanocomposite formation was also discussed.

• Applied Biological Chemistry
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• v.25 no.3
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• pp.173-176
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• 1982

The amino acids in the mucilage and its hydrolyzed products from Ulmus coreana, Nakai root were detected by thin layer chromatography. The mucilage contained 10 kinds of amino acids; alanine, aspartic acid, glutamine, glutamic acid, hydroxyproline, isoleucine, leucine, proline, phenylalanine and tyrosine. In the hydrolyzed mucilage 14 kinds of amino acids were detected; alanine, aspargine, arpartic acid, glutamine, glutamic acid, hydroxyproline, isoleucine, leucine, methionine, proline, phenylalanine, serine, tyrosine and valine.