• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.935-942
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• 1994

Two types of ABS were prepared from diffrent types of rubber, and blends of the ABS and PMMA were compounded and evaluated in terms of morphology, mechaincal and rheological properties. In addition, the effect of carbon black in the ABS/PMMA blends were studied. With increasing PMMA content, flexural modulus, tensile yield strength, and surface gloss of the blends increased, but elongation at break and Izod Impact strength decreased. With carbon black addition, mechanical properties were generally decreased. Effects of the type of ABS, and carbon black on melt properties were also studied.

• Fire Science and Engineering
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• v.18 no.3
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• pp.9-17
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• 2004

The values of physical properties of the inert gases of Ar, $N_2$, $CO_2$ were calculated by the empirical equations. The regression coefficients were obtained by the experimental data and the resulting calculated values. For the empirical equation with a lower regression coefficient, a new correlation was suggested. At an atmosphere pressure, the empirical equation was confirmed by the experimental values for the viscosity, density, saturated pressure, and surface tension of Ar, $N_2$, $CO_2$. The correlation coefficients of the empirical equations proposed in this work was higher than 0.99.

• Polymer(Korea)
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• v.31 no.5
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• pp.379-384
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• 2007

The nanocomposites with inorganic nano powder, improved thermal stability, were prepared by urethane polymerization. The structure and surface properties of the nanocomposites were determined by X-ray diffraction and FT-IR, respectively. The thermal stabilities were studied using TGA and DSC. Their morphologies and mechanical properties were observed by SEM and UTM. As a result, the nanocomposites with MMT led to the increase of the silicate layers. The distance between layers of the nanacomposites with MMT was increased by $7.5{\AA}$ and the new peaks at $1038cm^{-1}$ were shown in the presence of the Si-O groups on the silica. The thermal stabilities of the nanocomposites were higher than those of pore polyurethane matrix. The nanocomposites had higher in mechanical properties than the pure polyurethane matrix.

• Journal of Adhesion and Interface
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• v.16 no.2
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• pp.63-68
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• 2015

We synthesized thermoplastic polyurethane elastomer containing carboxylic acid group and TPV (thermoplastic vulcanizate). We measured the mechanical, grip, debris, contact angle and adhesion properties according to introducing acid group in elastomer structure. Mechanical and wet slip properties were improved because of the hydrogen bonding by introduction of acid group. Also adhesion strength was increased as increasing of surface polarity by carboxylic acid group. The debris property of TPV made from TPU containing carboxylic acid group was improved.

• Polymer(Korea)
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• v.32 no.1
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• pp.31-37
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• 2008

The effect of MMT on mechanical properties of CTBN toughened epoxy nanocomposite is studied. In case of CTBN toughened epoxy nanocomposite with modified MMT, it is found that the enhancement of toughness and tensile properties are exhibited in CTBN toughened epoxy nanocomposite with modified MMT From the results of fractured surface morphology of sample, it is clearly shown that the improved mechanical properties can be obtained in CTBN toughened nanocomposite due to the significant energy dissipation mechanism by MMT loading.

• Elastomers and Composites
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• v.38 no.2
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• pp.128-138
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• 2003

It goes to be serious with environmental pollution because of great number of waste tires scrapped each you. That is why there are lots of studies for efficient recycle. We tried to reduce particle size of the waste tire powder using a new technology of self-designed grinding machine (SDGM) and ultrasonic treatment. The purpose of this study is to improve the physical properties of reduced waste tire powder. We investigated the fine powder by particle size distribution(PSD) analysis. And also we examined the physical and mechanical properties and cross-link density at various particle sire. Also we carried out morphological studies after making the products by SEM.

• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.9-23
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• 2010

In current design practice, the shear wave velocity (Vs) of the core and rock-fill zone of a dam, one of the characteristics essential for seismic response design, is seldom determined by field tests. This is because the borehole seismic method is often restricted in application, due to stabilisation activities and concern for the security of the dam structure, and surface wave methods are limited by unfavourable in-situ site conditions. Consequently, seismic response design for a dam may be performed using Vs values that are assumed, or empirically determined. To estimate Vs for the core and rock-fill zone, and to find a reliable method for measuring Vs, seismic surface wave methods have been applied on the crest and sloping surface of the existing 'M' dam. Numerical analysis was also performed to verify the applicability of the surface wave method to a rock-fill dam. Through this numerical analysis and comparison with other test results, the applicability of the surface wave method to rock-fill dams was verified.

• Polymer(Korea)
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• v.38 no.1
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• pp.74-79
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• 2014

Microfibrillated cellulose (MFC) was chemically modified with two different silane coupling agents (3-aminopropyltriethoxysilane and 3-mercaptopropyltriethoxysilane) and lauroyl chloride. The surface modification of MFC was confirmed by infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), and contact angle measurements. Composite paper was successfully prepared with surface modified MFC and polyamide (PA) fiber. The surface modification of MFC not only prevented aggregation of MFC but also improved adhesive property between PA fiber and surface modified MFC. It was impossible to prepare papers of only PA fiber because there is no binder to connect PA fibers. That is, surface modified MFC as a binder in PA fiber played a crucial role in making composite paper. Composite paper with silane modified MFC showed higher tensile strength and modulus than composite paper with lauroyl moiety modified MFC. The structure, morphology, and mechanical properties of composite paper were analyzed by scanning electron microscope (SEM) and universal testing machine (UTM).

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.10a
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• pp.181-186
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• 1997

석탄회의 재활용율을 높이고자 비가소성 원료인 석탄회를 첨가한 슬립 및 고형화 소지의 유동학적 고찰을 하였고, 이들을 이용하여 주입성형 후 소성한 시편의 물성들을 측정하였다. 석탄회가 50wt.%이상 대체된 슬립의 경우 해교 기구는 점토내 입자의 정전기적 반발력 보다는 석탄회에 포함된 cenosphere 입자표면의 물유리 흡착에 의한 steric stabilization에 의한 것으로 판단되었다. 응집된 슬립은 전형적인 thixotrophy 현상을 나타내는 반면 분산후 재응집된 슬립은 점도가 계속 증가하는 겔화현상을 나타내어 망목구조를 갖는 성형체를 제조할 수 있었다. 석탄회 대체율 50wt.%의 소성체에서 가장 우수한 물성치를 얻을 수 있었으며, 대체율 70wt.%까지의 주입성형이 가능하였다.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.369-371
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• 2003

젤형 인공피부의 약한 물성을 보완하기 위해 스폰지형 인공피부가 개발되었으나 다공성 표면구조 때문에 세포의 배양이 어려운 문제점이 남아 있었다. 이 다공성 구조를 섬유모세포의 장기 배양으로 ECM으로 채우기 위해서는 3주이상의 긴 시간이 필요하며 그 위에 상피층 배양하기 위해서는 2주 이상의 시간이 추가로 소요되기 때문에 환자에게 이식할 적절한 시기를 놓칠수가 있다. 따라서 본 연구결과로 단기일 내에 전층 인공피부를 배양함으로서 적절한 이식시기를 맞출수가 있으며 이러한 기저막이 부착된 스폰지구조는 물성도 향상되어 이식시 조작이 쉽고 볼합이 가능한 장점이 있다.