• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.9
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• pp.1572-1578
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• 2008

The effect of the organoclay_10A nanoparticles on the DSC and Structural and Dielectrics Properties(1Hz-1MHz) for epoxy/Organoclay_10A Nanocomposites has been studied. Dielectric properties of epoxy-Organoclay nanocomposites were investigated at 1, 3, 5, 7, 9 filler concentration by weight. Epoxy nanocomposites samples were prepared with good dispersion of layered silicate using power ultrasonic method in the particles. As structural analysis, the interlayer spacing have decreased with filled nanoparticles contents increase using power ultrasonic dispersion. The maximum increase interlayered spacing was observed to decease for above 5wt% clay loading. The other hand, as decrease with concentration filler of the layered silicate were increased dispersion degree of nanoparticles in the matrix. The interesting dielectric properties for epoxy based nanocomposites systems are attributed to the large volume fraction of interfacesin the bulk of the material and the ensuring interactions between the charged nanoparticle surface and the epoxy chains.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.6
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• pp.538-543
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• 2008

Nanostructured materials are attracting increased interest and application. Exciting perspectives may be offered by electrical insulation. Epoxy/Organoclay nanocomposites may find new and upgraded applications in the electrical industry, replacing conventional insulation to provide improved performances in electric power apparatus, e.g, high voltage motor/generator stator winding insulation, dry mold transformer, etc. In the paper work, the electrical and thermal properties of epoxy/organoclay nanocomposites materials were studied. The electrical insulation characteristics were analyzed through the permittivity characteristics. by analyzing the permittivity spectra, it was found that dielectric constant becomes smaller with increase frequency and becomes larger with increase temperature. This indicates restriction of molecular motion and strong bonds at the epoxy/organoclay nanocomposites. The morphology of nanocomposites obtained was examined using TEM and X-ray diffraction. It has been shown that the presence of polar groups leads to an increased gallery distance and partial exfoliation. Nevertheless, full exfoliation of clay platelets has not been achieved.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.226-227
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• 2007

Nanostructured materials are attracting increased interest and application. Exciting perspectives may be offered by electrical insulation. Epoxy/Organoclay nanocomposites may find new and upgraded applications in the electrical industry, replacing conventional insulation to provide improved performances in electric power apparatus, e.g, high voltage motor/generator stator winding insulation, dry mold transformer, etc. This paper shows that electrical and thermal properties of epoxy/organoclay nanocomposites insulating materials for dsc, dielectric constant, I-V characteristics, breakdown volatge, can improve significantly with respect to the basic, virgin materials.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.125-128
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• 2001

In this wort, the $Na^+-MMT$ has organically modified with silane intercalant to prepare the polymer/clay nanocomposites. The pH. X-ray diffraction (XRD), and contact angles were used to analyze the surface properties of clay and the exfoliation phenomenon of clay interlayer, The mechanical interfacial properties of epoxy/clay nanocomposites were investigated by three-point bending test. From the experimental results. the surface modification made by silane intercalant on clay surface leads to an increase of distance of silicate layers, surface acid value. and electron acceptor parameter of organoclay. The treatments are also necessary and useful for epoxy to intercalate into the interlayer by interacting of electron donor-accepter between basic epoxy and clay surface. The mechanical interfacial properties of the nanocomposites was improved by the presence of dispersed clay nanolayer containing low content of organoclay in comparison with the conventional, which increase the interfacial adhesion between dispersed clay and epoxy resins.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.39-40
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• 2008

유기용매를 사용한 나노분산체의 경우, 유기용매를 완전하게 제거 것은 극히 어렵다. 이는 유기용매와 유기고분자와의 일부 반응되는 경우가 발생되어 전기적 물성에 영향을 줄 수 있다. 본 연구는 친환경적인 분산기법으로 물리적 분산기법을 제안하는 바이다. 양호한 분산체를 얻기위해 균질한 상태인 마이크로적 분산기법과 층상실리케이트인 층간사이에 고분자인 에폭시분자가 삽입되어 박리가 양호하게 일어나게 하는 나노적인 분산기법을 통시에 적용하여 분산이 훌륭하게 일어나는 경우를 개발하였다. 마이크로적인 분산을 위해 사용된 Homogenizer의 적용속도와 적용시간에서 원형인 Organoclay_10A Powder의 d-spacing이 262%, 263%로 증가되는 결과를 얻었다. 또한 DSC의 유리천이온도 분석에서도 적용시간의 증가에 따라 유리천이온도가 되어 원형에폭시수지에 비하여 $9^{\circ}C$상승된 결과를 얻을 수 있었다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.97-97
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• 2010

A new electric application method was developed to prepare epoxy/organoclay nanocomposite for the electrical insulation in the AC electric fields and it could be also used in the field of various viscous polymer/organoclay systems. The applied AC electric field condition was as follows; (1) inter-electrode distance: 40 mm, (2) application voltage: 3-11 kV, (3) frequency: 60~1,000 Hz, and (4) application time: 0~60 min. To characterize the epoxy/clay nanocomposite, WAXS and TEM analyses were confirmed. In order to explain how the organic modifier affects the exfoliation phenomena, a mechanism of the oscillating collision of the quaternary ammonium head was proposed and the effects of the AC voltage and frequency and the organoclay content were studied.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.281-282
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• 2008

고압절연용 에폭시-나노콤포지트의 전기적, 기계적, 열적특성이 동반적 물성의 상승을 가져오기 때문에 활발한 연구가 진행 중에 있다. 에폭시 메트릭스 내에서 유기화된 층상구조를 갖는 나노입자의 분산정도에 따라 여러 가지 물성에 영향을 나타내고 있다. Centrifugal 분산기법으로 나노콤포지트제조시 에폭시분자의 층간내로 충분한 삽입으로 박리가 발생하였다. 전기적 특성로서 기본적 구조적 특성인 X-RD특성과 TEM의 관찰로 분산을 확인할 수있었고, DSC의 측정으로 가교도를 알 수 있는 Tg값이 원형수지에 비하여 $11^{\circ}C$향상된 여러종류의 나노콤포지트를 개발하였다. 유전특성 및 절연파괴 특성으로도 원형수지에 비하여 나노콤포지트의 향상된 특성을 얻을 수 있었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.749-754
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• 2008

A large number of studies on the various characteristics of epoxy-layered silicate nanocomposites, such as electric and mechanical, morphology have been conducted and contributed to improve their characteristics. However, studies on the effects of its thermal conductivities in the thermal properties are not enough, even though there are some excellent evaluations for its insulation performances. Thermal properties will cause thermal degradation and significantly affect the reliability of these epoxy-layered silicate nanocomposites. In the results of the analysis of epoxy-layered silicate nanocomposites $T_g$ for various types of organoclays (10A, 15A, 20A, 30B, and 93A), it showed an excellent thermal property of 10A. Also, it represented low values in storage modulus and mechanical Tan (Delta) at a high temperature section 140$^{\circ}C$ and excellent thermal properties due to its movement to the high temperature section in the case of the property of 10A in the measurement of DMA elastics and mechanical losses. In the results of the measurement of thermal conductivities, power ultrasonic applications represented a significant increase in thermal conductivities in the case of the applications of power ultrasonic and planetary centrifugal mixers. Based on these results, it is necessary to perform related studies because it can be applied as useful materials for future power facilities applications in mold and impregnate insulation.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1340-1341
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• 2008

에폭시-Organoclay 나노콤포지트를 두가지 분산기법으로 적용하여 제조하였다. 하나는 Centrifugal 기법과 또다른 하는 강력초음파를 이용하여 제조하였다. 초음파를 적용하지 않고 Centrifugal만으로 제조된 나노콤포지트를 충진함량별 교류/직류정극성 전압을 인가한 절연파괴 특성과 Organoclay 종류별 교류절연파괴 특성을 연구하였다. 충진함량 특성으로 원형에비하여 나노콤포지트의 절연파괴 특성을 향상되었고, 함량이 5wt%까지는 거의 같은 파괴강도를 나타내었고, 이후 함량이 증가될수록 오히려 감소되는 경향을 나타내었다. 종류별 Organoclay의 경우 10A특성이 가장 높은 교류절연파괴 강도를 나타내었다. 초음파를 적용한 경우 함량별 교류절연파괴 강도 역시 초음파를 적용하지 않은 경우와 유사한 함량별 절연파괴 경향을 나타내었다. 파괴강도는 초음파를 적용한 경우가 월등히 높은 47.3%가 향상된 결과를 나타내었다. 이는 향후 몰딩용 및 함침용 절연재료로서 응용될 고압절연물에 크게 이용될 것으로 본다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.296-297
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• 2008

층상실리케이트 나노입자가 충진된 에폭시수지를 분산정도 향상을 위해 즉, 층상실리케이트 층간간경의 삽입과 박를 향상시키기 위해 분산제를 첨가하였고, 초음파 적용으로 분산시켰다. 그 결과 분산제 종류에따라 분산정도인 X-RD 특성이 서로다른 결과를 얻었다. 절연성능을 평가하기위해 단시간 절연파괴강도와 장시간 절연파괴특성인 트리시스템을 이용하여 절연파괴시간 및 측정하였다. 이와같은 결과에대한 통계적인 분석으로 Weibull plots를 이용하였고 그 결과 분산제가 첨가된 나노콤포지트의 기울기 파라미터인 $\beta$값의 결과로부터 나노콤포지트 우수성을 확인 할수있었다.