• Membrane Journal
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• v.15 no.1
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• pp.22-33
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• 2005

Asymmetric PVDF membranes were prepared by the phase inversion from casting solutions containing PVDF, NMP as solvent and 1,4-dioxane, DGDE, acetone, or GBL as additives by immersing them in water. The effects of various additives on the casting solution properties, permeation properties, and membrane structures were investigated. Low miscibility of 1,4-dioxane, DGDE and acetone with the coagulant (water) compared with NMP resulted in reducing the membrane pore size. When DGDE is used as an additive, the pore size was reduced because of its incipient sharp interface formation in the water. GBL increased membrane pore size because of its polarity compared to that of NMP. The PVDF membranes with various pore sizes could be obtained by controlling the amount of additive. The effect of mixed solvent (aqueous and non-aqueous solution) on permeation through membrane was investigated. Not only solution viscosity but surface tension affected solvent permeation.

• Elastomers and Composites
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• v.43 no.1
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• pp.8-17
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• 2008

Styrene-butadiene rubber(SBR) has good abrasion resistance, miscibility, and anti-vibration property. however, it is easily damaged by ozone and swelled by hydrocarbon fluids because of unsaturation part in main chain, that causes loss of visco-elasticity and reduction of product's life cycle. Therefore, object of this study is to cope with this problem. SBR is blended with various proportion of ethylene-propylene-diene terpolymer(EPDM), which has excellent ozone and oxygen resistance, to improve physical properties and ozone resistance, and diverse analytical techniques are used to measure morphology, glass transition temperature$(T_g)$, ozone-resistance, degradation temperature, static spring constant, hardness for considering a suitability for anti-vibration industrial product. We found that the blend consisting of SBR 70% and EPDM 30% showed no crack after ozone test and good miscibility between SBR and EPDM from this study.

• Journal of the Korean Institute of Gas
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• v.27 no.1
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• pp.23-32
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• 2023

In this study, the Al₂O₃ nanofluid was synthesized as an additive for improving the injection efficiency and storage capacity of carbon dioxide (CO₂) in a depleted sandstone reservoir or deep saline aquifer. As the base fluid, deionized water (DIW) and saline prepared by referring to the composition of API Brine were used, and the fluid was synthesized by using Al₂O₃ nanofluid with CTAB (cetyltrimethyl-ammonium bromide), a cationic surfactant. After that, the dispersion stability was evaluated by using visual observation, dynamic light scattering (DLS), transmission electron microscope (TEM), and miscibility test. As a result, it was presented that stable nanofluid without agglomeration and precipitation after reaction with 70,000 ppm of brine could be synthesized when the nanoparticle concentration was 0.05 wt% or less.

• Journal of Korea Foundry Society
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• v.22 no.5
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• pp.238-244
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• 2002

Water and oil were completely synthesised with ultrasonic vibration energy irradiation. Pure Pb were added into Al melt during irradiated the ultrasonic vibration energy in 750. And the ultrasonic vibration energy was applied to Al-Pb melt to enhance the miscibility. Microstructural analysis, thermal analysis and X-ray diffraction analysis were carried out to evaluate the effect of the ultrasonic vibration energy on the castability and microstructural reliability. (1) Using the ultrasonic vibration energy irradiation, the complete mixing of water and oil was obtained. (2) The microstructure was refined by the application of ultrasonic vibration energy in Al-Pb alloys. (3) Relatively large Pb particles, $5{\mu}m$ were most distributed alone the grain boundaries with fine Pb particles evenly distributed in the matrix. (4) The solubility of Ph in Al-Pb alloys was increases up to 5% with the application of ultrasonic vibration energy.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.289-290
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• 2003

Polymer blending constitutes a most useful method for the improvement or modification of the physicochemical properties of polymeric materials. So polymer blends have gained an increasing interest in both industrial and scientific fields. Some of the polymer blends exhibit unusual properties, unexpected from homopolymers. An important property of a polymer blend is the miscibility of its component, because it affects the mechanical properties, the morphology, its permeability and dogradation [1,2]. (omitted)

• The Korean Journal of Rheology
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• v.1 no.1
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• pp.20-28
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• 1989

비닐 알코올의 함량이 62(EVOH-62) 및 71(EVOH-71) mole%인 에틸렌 비닐알코올 공중합체와 나일론(나일론-6, 나일론-6/12 및 나일론-12)과의 블렌드를 이축압출기에서 제 조하였으며 이들블렌드의 형택학 및 유변학적 성질을 SEM, TEM 및 RDS로 측정하였다. EVOH-61/나일론-6 및 EVOH-7/나일론-6 블렌드는 나일론의 조성이 많은 영역에서는 균 일상을 EVOH 조성이 많은 영역에서는 미세한 상분리(약 0.2$\mu$)를 나타내었다. 한편 EVOH-71/나일론-6/12 및 EVOH-71/나일론-12 블렌드는 상분리가 뚜렸하였으며 EVOH조 성이 많은 영역에서는 피브릴화가 나타났다. 낮은 진동주파수 영역에서 점도 대 조성곡선은 전반적으로 양의 편차를 보였으나 Cole-Cole plot은 나일론-6과의 블렌드가 나일론-6/12나 나일론-12와의 블렌드에 배해 유변학적인 측면에서보다 상용성이 우수함을보였다.

• Macromolecular Research
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• v.9 no.1
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• pp.30-36
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• 2001

Polybutadiene latex grafted (g-PB) in g-PB/SAN blends, i.e., acrylonitrile-butadiene-styrene terpolymer (ABS) were partially replaced by acrylonitrile-butadiene copolymer (NBR) with various acrylonitrile (AN) contents. Changes in morphology, physical and rheological properties were examined. The dispersed size of NBR was decreased as the miscibility with matrix SAM, was increased by increasing AN content in NBR upto 50 wt%. Impact strength was enhanced about two-fold due to the NBR dispersed with a slight larger size than the original g-PB. Gloss was effectively reduced as the particle size of NBR was increased. Tensile yield strength was decreased, and elongation at break or yield behavior at low shear rate were increased as g-PB was partially replaced by NBR having AN content less that 40 wt%.

• Macromolecular Research
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• v.9 no.1
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• pp.37-44
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• 2001

A premixing effect for the properties of carbon black-filled rubber compounds was investigated using biblends of natural rubber (NR), styrene-butadiene rubber (SBR), and butadiene rubber (BR). Degree of mixing of the biblends was controlled by preblending time of 0.0, 2.5, and 5.0 min. Mooney viscosities of the compounds decreased by increasing the preblending time. Of three carbon black-filled compounds of NR/SBR, NR/BR, and SBR/BR compounds, only the SBR/BR blends showed a specific cure characteristics depending on the preblending time. For the bound rubber composition, the NR content was higher than SBR and BR. The difference in the rubber composition ratio of the bound rubber became smaller with increasing the preblending time. Physical properties of the vulcanizates such as hardness, modulus, tensile property, abrasion loss, and tans were also compared. Differences in properties of the compounds were discussed with miscibility of the dissimilar rubbers and degree of mixing.

• Textile Coloration and Finishing
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• v.10 no.6
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• pp.33-41
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• 1998

이 연구는 염색성이 열악한 polypropylene(PP) 섬유의 염색성을 개선하기 위해 추진한 것이다. 연구목적에 따라서 PP 섬유를 개질하기 위해 1차 cellulosic유도체를 추출하고 이 유도체와 PP를 9：1의 혼합비율로 섞어 master batch를 만든 다음 master batch 17%와 PP를 blending하여 개질 PP를 만들었다. 이렇게 제조된 개질 PP는 혼합된 변성 cellulosic polymer의 영향으로 착색이 심하게 되어 있으므로 이를 표백하는 것을 이 연구의 목적으로 하였다. 연구결과 blend한 개질 PP(Grand P)의 혼화성이 우수하였고, 아염소산나트륨에 표백적성을 가지며, 표백의 최적조건은 표백제의 농도가 0.1% $NaClO_2$, 표백온도 $70^\circ{C}$, 표백시간 30분이었다.

• Transactions on Electrical and Electronic Materials
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• v.15 no.6
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• pp.305-308
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• 2014

Organosilyl-modified and star-shaped poly (${\varepsilon}$-caprolactone) (m-PCL) was prepared, and added to polymethylsilsesquioxane (PMSSQ), to make composites. The end groups of m-PCL are chemically similar to PMSSQ, and m-PCL mixed well with PMSSQ in the composite. Porous PMSSQ film was made by further calcination of the composite film at elevated temperature. m-PCL-templated PMSSQ and the as-prepared porous PMSSQ were structurally, optically, and thermally characterized in thin films. The chemical binding of m-PCL and PMSSQ effectively suppressed the phase separation of PMSSQ and m-PCL during the curing process. After calcination at elevated temperature, there remained many pores in the PMSSQ matrix. The refractive indices of the resulting porous PMSSQ thin films decreased with increase of the film porosities, depending on the initial m-PCL loadings.