• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.895-901
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• 1998

To extract insoluble proteins and improve functional properties of sesame meal proteins was treated with phytase and protease from Aspergillus sp. It was found that the optimum pH, optimum temperature, optimum treatment time and optimum unit of enzyme for extraction of protein were pH $10{\sim}12$ (alkaline), $60^{\circ}C$, 11 hr. and 900 units of phytase and 60 units of protease, respectively. The foaming capacity, foaming stability, oil absorption and water absorption of sesame meal protein after treatment with phytase and protease were increased as compared to the control.

• Journal of the Korean Applied Science and Technology
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• v.33 no.4
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• pp.802-812
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• 2016

Silicone foam is very useful as flame resistant material for many industrial areas such as high performance gasketing, thermal shielding, vibration mounts, and press pads. A silicone foam was prepared through simultaneous crosslinking and foaming by hydrogen condensation reaction of a vinyl-containing polysiloxane (V-silicone) and a hydroxyl-containing polysiloxane (OH-silicone) with hydride containing polysiloxane (H-silicone) in the presence of platinum catalyst and imorganic filler at room temperature. This is more convenient process for silicone foam manufacturing than the conventional separated crosslinking and foaming systems. Funtionalized silicones we used in this experiment were consisted with a V-silicone containing 1,0 meq/g of vinyl groups and a viscosity of 20 Pa-s, an OH-silicone with 0.4 meq/g of hydroxyl groups and a viscosity from 50 Pa-s, and an H-silicone containing 7.5 meq/g of hydride groups and a viscosity of 0.06 Pa.s. The effects of compositions of functionalized silicones and additives, such as catalyst and filler on the structure and mechanical properties of silicone foam were studied. 0.5 wt% of Pt catalyst was enough to accelerate the foaming rate of silicone resins. The addition of OH-silicone with lower viscosity accelerates the initial foaming rate and decreases the foam density, but the addition of V-silicone with lower viscosity reduces the tensile strength as well as the elongation. The final foam density, tensile strength, and elogation of silicone foam prepared under the SF-3 condition increase maximum to $0.58g/cm^3$, $3,51kg_f/cm^2$, and 176 %, repectively. We found out the filler alumina also played an important role to improve the mechanical properties of silicone foams in our foaming system.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.30 no.1
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• pp.63-72
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• 2024

Poly (butylene adipate-co-terephthalate) (PBAT) is one of the representative biodegradable polymers with high ductility and processability to replace petroleum-based polymers. Many investigations have been conducted to broaden the applications of PBAT in a variety of industries, including the food packaging, agricultural mulching film, and logistics and distribution fields. Foaming process is widely known technique to generate the cell structure within the polymer matrix, offering the insulation and light weight properties. However, there was no commercially feasible foam product based on biodegradable polymers, especially PBAT, and maintaining a proper melt viscosity of the polymer would be a key parameter for the foaming process. In this study, chemical foaming agent and cross-linking agent were introduced to PBAT, and a compression molding process was applied to prepare a foam sheet. The correlation between cell morphological structures and mechanical and physical properties was evaluated. It was found that PBAT with foam structures effectively reduced the density and thermal conductivity, allowing them to be suitable for applications such as insulation and lightweight packaging or cushion materials.

• Journal of the Korean Ceramic Society
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• v.50 no.2
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• pp.93-102
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• 2013

Macro porous ceramics possessing controlled microstructures and chemical compositions have increasingly proven useful in the industrial sphere. Their sintered structures have found application in both established and emerging, areas such as thermal insulation in buildings, filtration of liquids and molten materials, refractory insulation, bone scaffolds and tissue engineering. Stable ceramic foams can be formed by wet chemical methods using inorganic particles(e.g., $Al_2O_3$ or $SiO_2$). The wet foams are dried and sintered with improved porosity and mechanical properties. This review examines the different techniques used to prepare porous ceramics from ceramic foams, focusing on the explanation of this versatile method of direct foaming from the past to the present. Comparisons of the processes and the processing parameters are explained with the produced microstructures.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1630-1635
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• 2005

The microstructure of the parts made by the microcellular injection molding process influence properties, including impact strength, tensile strength and density of material. Microstructure of microcellular plastics is divided into core foaming region and solid skin region. Core foaming region is influenced by pressure drop rate, viscosity and cell coalescence. However, actual mechanism of the skin layers is not known despite its importance. The study on the skin layer is getting important because foaming rate of the plastics is determined by the thickness ratio of the skin layer. Especially in case of large molded part, control of the skin layer is needed because skin layer thickness is changed largely. Therefore it is necessary to study variation in skin layer thickness with processing parameters. In this paper, the influence of temperatures in the mold cavity on the skin layer s thickness was also addressed. In addition, the relationship between the temperature distributions across cavity of the mold with impact strength on parts made with the microcellular injection molding process was addressed. In addition, the method to predict the variation in skin layer thickness with mold temperature is discussed.

• Polymer(Korea)
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• v.25 no.5
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• pp.707-718
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• 2001

Polypropylene (PP) exhibits many beneficial properties such as low density high thermal stability, chemical resistance, good processability and recyclability. However, only limited research has been done on expanded polypropylene (EPP). In this study, we were trying to prepare EPP with chemical blowing agent. Ethylene-octene copolymer (mPE) was melt blended with PP to enhance melt fluidity of PP at processing temperature and to make more flexible foamed material. Prior to foaming, phase morphology of PP/mPE blends were investigated to examine the effect of phase morphology on the foaming ratio and cell structure of foams. Phase morphology of PP/mPE blends were affected by the content of mPE and mixing torque ratio. At the same composition, it was affected by mixing rpm. High blowing ratio and stable cell structure were obtained in the blend which has the continuous PP matrix with dispersed droplets of mPE.

• Polymer(Korea)
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• v.26 no.4
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• pp.508-515
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• 2002

The effects of the crosslinking caused by irradiation dose, molecular weights of the foaming materials, and various foaming processes on the foam structure of the polypropylene (PP) were investigated. The maximum gel content of the PP was 48% when the sheet was irradiated with 3.2 Mrad. This high gel content improved the cell structures by providing high thermal stability. The increase of both the gel content and structural development were stopped at the irradiation dose exceeding 3.2 Mrad. The increase of the molecular weights served to help produce a foam with particularly fine and even cell structures, along with improved thermal stability as well.

• Journal of the Korean Applied Science and Technology
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• v.14 no.3
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• pp.71-77
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• 1997

Low foaming acidic degreasing agent(LFADAs) were prepared by blending sorbitol, n-octanoic acid, MJU-100A, Tetronix T-701, Na-dioctyl sulfosuccinate, Demol C, and phosphoric acid. The physical properties of LFADAs tested with aluminum specimen showed the following results ; when 3wt% LFADA-6 was performed at $70^{\circ}C$, the degreasing rate was 95% which is comparitively good, and the percentage of etching was 0.275% which was found to be less than that of commercialized product. When 20wt% of LFADA-6 was added at $65^{\circ}C$, the percentage of derusting was 92% and the good defoaming effect proved by following low foaming power tests respectively : Ross and Miles, and Ross and Clark methods.

• Proceedings of the Korea Concrete Institute Conference
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• 1991.10a
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• pp.99-106
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• 1991

Result of an experimental study on the manufacture, the mechanical properties and waterightness of pitch-based carbon fiber reinforced fly ash.cement composites are presented in this paper. The carbon fiber reinforced fly ash.cement composites using early strength cement, silica powder and a small amount of stylene butadiene rubber latex are prepared with carbon fiber, foaming agents and mixing conditions. As a result, the mechanical and plysical properties such as compresive, tensile and flectural strengths, watertightness and cement composites are improved by using a small amount of stylene butadiene rubber latex.

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.109-117
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• 1993

To investigate the effects of sodium alginate, gum karaya and gum arabic on the foaming properties of sodium caseinate, surface tension, specific viscosity, turbidity, foaming ability and foam stability of the caseinate solution with added gums were examined. Surface tensions of the 5%(w/v) protein solutions containing gums at pH 7.0 and 8.0 were $43.7{\sim}44.7dyne/cm$ and $43.6{\sim}44.0 dyne/cm$, respectively. Specific viscosities of the solutions with 0.2 and 0.3% sodium alginates were 15.6 and 39.1 at pH 7.0 (control, 2.8), and 12.1 and 8.2 at pH 8.0 (control, 2.6), respectively. Turbidities were $69.5{\sim}74.0$ at pH 7.0 and $68.0{\sim}72.5$ at pH 8.0. The optimum conditions for foaming ability of the solutions were 0.1% conc. and 15 min whipping in addition of sodium alginates; 0.2% conc. and 20 min whipping in gum karaya; 0.1% conc. and 10 min whipping in gum arabic. For foam stability optimal concentrations were 0.3% in sodium alginate and gum karaya at pH 7.0 and 0.2% at pH 8.0. Addition of sodium alginates was most effective to increase foam stability of the solution, but was not effective to increase foaming ability. At same pH, surface tensions and turbidity of the solutions were related to foaming ability and specific viscosities were related to foam stability.