• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.345-353
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• 2013

This paper discusses the experimental results in an effort to understand the tracking and erosion resistance of the micro and nano size $Al_2O_3$ filled silicone rubber (SIR) material which has been studied under the AC voltages, with ammonium chloride as a contaminant, as per IEC 60587 test procedures. The characteristic changes in the tracking resistance of the micro and nano size filled specimens were analyzed through leakage current measurement and the eroded masses were used to evaluate the relative erosion and tracking resistance of the composites. The fundamental, third and fifth harmonic of the leakage current during the tracking study were analyzed using moving average current technique. It was observed that the harmonic components of leakage current show good correlation with the tracking and erosion resistance of the material. The thermogravimetry-derivative thermo gravimetric (TG-DTG) studies were performed to understand the thermal degradation of the composites. The physical and chemical studies were carried out by using scanning electron microscope (SEM), Energy Dispersive X-ray analysis (EDAX) and Fourier Transform Infra-red (FTIR) Spectroscopy. The obtained result indicated that the performance of nano filled SIR was better than the micro filled SIR material when the % wt. of filler increased.

• 한국전기전자재료학회논문지
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• 제27권8호
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• pp.522-527
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• 2014

In this study, using the silicone rubber sample of $4cm{\times}4cm{\times}0.1cm$ for low voltage cable, the electrostatic electrification properties of three samples that the conductive Al of 0%, 25%, and 50% is attached to the surface of sample was measured. The following conclusion was obtained through this experiment. 1) In case of the sample which has the Al area of 50%, the higher the humidity to 90% in the temperature of $10^{\circ}C$, the electrostatic electrification voltage was reduced about 0.25 kV to 0.02 kV, and it confirmed that the electrostatic electrification voltage was in constant about 0.02 kV in the temperature over $20^{\circ}C$. 2) Increasing the Al area of samples of 0%, 25%, and 50% in temperature of $10^{\circ}C$, it confirmed that the electrostatic electrification voltage was reduced by about 2.67 kV, 2.02 k, 0.21 kV. 3) This study shows that the conductor, followed by temperature and humidity affects the electrostatic electrification voltage.

• 한국전기전자재료학회논문지
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• 제34권5호
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• pp.364-370
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• 2021

In this study, the dielectric properties of flame retardant silicone rubber mixed with the amount of silica 50~65 phr were measured at frequencies ranging from 1 to 2.7 MHz and temperature ranges from 30℃ to 160℃. The permittivity decreased with higher frequencies and higher temperatures, and tanδ are thought to have decreased due to the increased heat oxidation of the methyl group bound to Si, which increased the hardness of silicone rubber. FT-IR analysis of specimen mixed with SiO₂ of 50~65 phr showed oscillations of OH groups bound to SiO₂ between wavenumber 3,600 and 3,300. As a result of analyzing surface components by Energy Dispersive X-ray (EDX) on all specimens mixed with SiO₂ of 50 to 65 phr, all specimens contained Si, and the analysis by field emission scanning electron (FE-SEM) confirmed that about 1~5 ㎛ particles were distributed regularly on the surface of the specimens.

• Design & Manufacturing
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• 제17권1호
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• pp.1-5
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• 2023

In multi-material injection molding, since two or more materials with different process conditions are used, it is essential to maximize process efficiency by operating the cooling or heating system to a minimum. In this study, Liquid silicone rubber (LSR) that can be cured at a low temperature suitable for the multi-material injection molding was selected and the cure behavior according to the process conditions was analyzed through differential scanning calorimetry (DSC). Dynamic measurement results of DSC with different heating rate were obtained, and through this, the total heat of reaction when the LSR was completely cured was calculated. Isothermal measurement results of DSC were derived for 60 minutes at each temperature from 80 ℃ to 110 ℃ at 10 ℃ intervals, and the final degree of cure at each temperature was calculated based on the total heat of reaction identified from the Dynamic DSC measurement results. As the result, it was found that when the temperature is lowered, the curing start time and the time required for the curing reaction increase, but at a temperature of 90 ℃ or higher, LSR can secure a degree of cure of 80% or more. However, at 80 ℃., it was found that not only had a relatively low degree of curing of about 60%, but also significantly increased the curing start time. In addition, in the case of 110 ℃, the parameters were derived from experimental result using the Kamal kinetic model.

• Design & Manufacturing
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• 제17권2호
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• pp.27-32
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• 2023

Liquid silicon rubber (LSR) has fine thermal compatibility and is widely used in various fields such as medical care and automobiles because it is easy to implement products with good fluidity. With the recent development of flexible sensors, the focus has been on manufacturing conductive elastomers, such as silicone as elastic materials, and carbon black, CNT, and graphene are mainly used as nanomaterials that impart conductive phases. In this study, mechanical behavior and curing behavior were measured and analyzed to manufacture a CB-LSR complex by adding Carbon Black to LSR and to identify properties. As a result of the compression test, the elastic modulus tended to increase as carbon black was added. When the swelling test and the compression set test were conducted, the swelling rate tended to decrease as the content of carbon black increased, and the compression set tended to increase. In addition, DSC measurements showed that the total amount of reaction heat increased slightly as the carbon black content increased. It is considered that carbon black was involved in the crosslinking of LSR to increase the crosslinking density and have a positive effect on oil resistance reinforcement.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.332-333
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• 2006

The properties of a cable Insulate capacity between surfaces with the variation of the interfacial breakdown, the addition of silicon oil, the variation of pressure and interfacial roughness were investigated. The Insulate trouble of a power cable is out of the interfacial parts, which breakdown the insulate breakdown capacity in a power cable. In this study, the analysis of electric field and the phenomenon of interfacial breakdown were reported by varying the surfaces condition of silicon rubber, XLPE used for connection materials of a power cable.

• 한국전기전자재료학회논문지
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• 제25권9호
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• pp.732-737
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• 2012

This study made a specimen (contact surface size: $45\;mm{\times}0.02\;mm{\times}45{\sim}55\;mm$) with silicon rubber for low voltage cable with 50 phr silica filler. The electrification voltage of electrostatics were measured for different sizes of contact surface with the applied voltage of 10kV and the environmental settings of temperature ($25{\sim}40^{\circ}C$) and humidity (40~80%). The following conclusions were made. The electrification voltage of electrostatics decreased as the humidity increased. The electrification voltage of electrostatics increased as the temperature increased. The larger the surface size, the higher the electrification voltage of electrostatics. The property of the material had more effect on the relaxation time than the humidity.

• 동력기계공학회지
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• 제10권4호
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• pp.181-186
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• 2006

In this paper, a noncontact type torque meter using silicone rubber to measure the exact torque value and reduce a vibration and a noise, was developed. When planetary gear speed reducer runs, torque, RPM etc.. of motor change according to load or speed change. So, it needs a device to detect load's change or to diagnose the state of thewhole drive department by monitoring these result values. The noncontact type torque meter using silicone rubber that we're trying to develop this time is low-cost and can measure RPM and torque value simply. Also, it caculate a power using this value and indicate them on screen.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 유기절연재료 방전 플라즈마연구회
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• pp.40-43
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• 2003

전기방전에 대한 shed 재료의 열화내성과 우수한 발수성의 장기간 유지특성은 폴리머 애자의 장기성능에 있어서 가장 중요한 인자들이다. 애자 제조시 무결점 성형성 또한 중요한데 열화내성을 확보하기 위해 다량의 ATH의 첨가가 수반되기 때문에 적절한 process oil의 사용이 불가피하다. 사용하는 오일의 종류와 량에 따라 옥외절연물의 장기성능에 영향을 주는 표면발수성이나 방전내성은 크게 차이가 나는 것으로 밝혀지고 있다. 본 논문에서는 화학적 구조와 정도가 다른 몇 가지 실리콘 fluid들을 실리콘 고무에 처방하여 기본물성과 초고압 옥외절연물의 shed 재료로서 장기성능에 영향을 주는 방전열화내성과 표면발수성의 회복특성을 평가하였다. 실리콘 고무의 무결점 사출성형에 가소도가 중요한데 동일한 무기물 첨가조건에서 유사한 가소도를 갖게 하는데 필요한 량은 fluid들의 종류에 따라서 상당한 차이가 있었다. 특히 PDMS는 점도는 낮지만 분자량이 커서 많은 량이 첨가되어 기계적 특성저하가 크게 일어났다. 코로나 처리후 발수성 회복특성은 fluid들의 분자크기와 반응기의 종류에 따라 상당히 영향을 받았으며 분자가 클수록 초기회복속도는 다소 느려도 최종의 상시발수성은 다소 높게 유지되었으며 2일 이내에 거의 초기 접촉각으로 회복되었다. 내아크성은 무게손실이 적을수록 오차범위도 작은 안정된 특성을 보였으며 fluid들의 종류에 따른 무게손실의 차이는 크지 않았다. 트래킹 방전에 의한 무게 감소는 fluid의 분자가 크면서 페닐기를 가진 fluid들이 첨가된 고무가 우수한 특성을 보였다.

• Elastomers and Composites
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• 제50권3호
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• pp.210-216
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• 2015

Polyurethane modified silicone (PUMS) was synthesized from various molecular weights of polydimethylsiloxane (PDMS 2000, PDMS 6000, PDMS 20000), polypropyleneglycol with molecular weight of 3000 g/mol (PPG 3000) and 2,4-toluenediisocyanate (TDI) under tin catalyst. Their structures were confirmed by the measurement of FT-IR and $^1H-NMR$, and the thermal properties were studied from DSC and TGA. Glass transition temperature of PUMS exhibited exothermic peak at $-63{\sim}-69^{\circ}C$, and residual weight was 19~35% at $800^{\circ}C$.