• Transactions on Electrical and Electronic Materials
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• 제18권4호
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• pp.203-206
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• 2017

The effect of the content of microsilica and nanosilica continuously modified with hydroxy silane and epoxy-modified silicone in cycloaliphatic epoxy/microsilica/nanosilica composites (EMNCs) on the mechanical and water repellent properties was evaluated. Surface-modified micro- and nanosilica was well-mixed with a cycloaliphatic epoxy resin in the presence of polyester-modified polydimethylsiloxane (PEM-PDMS) as a dispersing agent using an ultrasonicator. Tensile and flexural tests were carried out using a universal testing machine (UTM). The water repellent property was evaluated by contact angle measurements of water on the composite surface. Tensile strength of the composite could be enhanced by 32.2% up to 91.4 MPa, and the flexural strength was raised to 122.0 MPa, which is 38.8% higher than that of neat epoxy. The contact angle of water on the composite was as high as $104.1^{\circ}$.

• Elastomers and Composites
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• 제44권3호
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• pp.260-268
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• 2009

Clay의 표면을 bis[(3-triethoxysilylpropyl)tetra sulfide (TSS)으로 처리하면 clay 표면의 소수성이 증가 될 뿐만 아니라 high temperature vulcanization 형 silicone rubber(HTV)와 화학적 반응이 가능하기 때문에 clay와 silicone rubber 사이의 상용성이 향상될 수 있을 것으로 예상되어 TSS를 이용하여 Na-MMT와 Fe-MMT의 silicate 층 표면에 tetra sulfide 그룹을 도입시킨 Na-$MMTS_4$와 Fe-$MMTS_4$를 각각 제작하였다. 이들 clay를 HTV silicone rubber와 compounding하여 silicone rubber/clay composites를 제작하였으며, clay의 종류 및 표면개질에 따른 silicone rubber 복합체의 열적안정성 및 기계적 물성을 평가하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권10호
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• pp.479-488
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• 2001

The effects of accelerated Ultraviolet (UV) radiation on High temperature vulcanized (HTV), Room temperature vulcanized (RTV) silicone rubber and two types of ethylene propylene diene terpolymer (EPDM) used for composite insulator were inverstigated by hydrophobicity class (HC), surface voltage decay after corona charging, SEM-EDS, FTIR and XPS. The contact angle in two kinds of silicone rubber was scarcely change, but EPDM occurred to the loss of hydrophobicity followed by surface cracking and chalking. The surface voltage decay on UV-treated silicone rubber and EPDM showed a different decay trend with UV treatment. EDS and XPS analysis indicated that the oxygen content increased with UV treatment time in all samples. For silicone rubber, the oxidized groups of inorganic silica-like structure increased with UV treatment time. The oxidized carbon of C=0, O=C-O in EPDM increased. These oxidized surface for each material had different electrostatic characteristics, so deposited charges were expected to have different impacts on their surface hydrophobicity. The degradation mechanism based on our results was discussed.

• 한국응용과학기술학회지
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• 제27권2호
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• pp.183-187
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• 2010

Core-Shell polymers of silicone dioxide-styrene system were prepared by sequential emulsion polymerization. In inorganic/organic Core-Shell composite particle polymerization, silicone dioxide adsorbed by surfactant sodium dioctyl sulfosuccinate (EU-DO133L) was prepared initially and then core silicone dioxide was encapsulated emulsion by sequential emulsion polymerization using styrene at the addition of potassium persulfate (KPS) as an initiator. We found that $SiO_2$ core shell of $SiO_2$/styrene structure was formed when polymerization of styrene was conducted on the surface of $SiO_2$ particles, and the concentration sodium dioctyl sulfosuccinate (EU-DO133L) was 0.5~2.0g. The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer and morphology of latex by scanning electron microscope(SEM).

• Elastomers and Composites
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• 제38권3호
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• pp.227-234
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• 2003

배합고무에 각종 표면처리제로 처리한 수산화 알루미늄을 무게비 100:20, 100:40, 100:60, 100:80 및 100:100으로 배합하여 고압애자용 실리콘 복합체(HVI SC)를 제조하였다. 배합 공정에서 지방산, 아크릴 실란 및 비닐 실란등의 표면처리제로 수산화 알루미늄을 표면처리하였다. 수산화알루미늄의 첨가량 및 표면처리제의 종류에 따른 기계적 특성 및 전기적 특성을 연구하였다. 수산화 알루미늄의 첨가량이 증가하면서 인장강도, 신장율 및 인열강도는 감소하였으며, 비닐 실란으로 표면처리한 수산화 알루미늄을 첨가한 HVI SC의 인장강도 및 탄성율은 지방산 및 아크릴 실란을 사용한 HVI SC 보다 우수하였다. 또한 비닐 실란을 사용한 HVI SC의 체적저항, 절연파괴강도 및 내트래킹 특성이 지방산 및 아크릴 실란을 사용한 HVI SC 보다 우수하였다. 표면처리제의 종류에 따른 실리콘 복합체의 고분자 충전작용은 결합고무 함량으로 검토하였다. 실험의 결과로는 비닐 실란을 표면처리제로 사용한 실리콘 복합체의 결합고무 함량이 다른 표면처리제를 사용한 것 보다 높았다 표면처리제의 종류에 따른 실리콘 복합체의 가교밀도는 Rheometer로 측정하였다 비닐 실란을 표면처리한 수산화 알루미늄을 충진한 실리콘복합체의 최대토크가 다른 표면처리제를 사용한 것들 중에 가장 높았다.

• 폴리머
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• 제27권1호
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• pp.3-8
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• 2003

말단에 수소화물기가 치환된 폴리실록산과 알릴 메타크릴레이트와의 히드로실릴레이션 반응을 통하여 폴리실록산 메타크릴레이트를 합성하였다. 또한 산 촉매 하에서 옥타메틸사이클로테트라실록산의 개환-부가반응을 통하여 분자량이 증가된 폴리실록산 메타크릴레이트을 합성하였다. 합성된 폴리실록산 메타크릴레이트는 $^1$H- 및 $^{29}$ Si-NMR로 구조를 확인하였다. 폴리실록산 메타크릴레이트는 실리콘 오일과 균일하게 혼합되었으며, 이 용액을 광 가교시켜 액상인 실리콘 오일이 수 백 nm 정도의 크기로 고르게 미세상분리된 폴리실록산 복합체 필름을 제조할 수 있었다. 주사전자현미경(SEM)을 이용한 모폴로지 관찰로부터 실리콘 오일의 함량이 작을수록, 매트릭스 물질인 폴리실록산 메타크릴레이트의 분자량이 낮을수록, 그리고 분산상 물질인 실리콘 오일의 분자량이 낮을수록 대체적으로 분산상의 크기가 작아짐을 확인하였다

• 한국응용과학기술학회지
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• 제26권2호
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• pp.199-204
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• 2009

Silicone dioxide absorbed polyoxyethylene alkylether sulfate (EU-S133D) surfactant was prepared. Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using Acrylate as a shell monomer and potassium persulfate (KPS) as an initiator. We found that when Acrylate core prepared by adding 2.0 wt% EU-S133D, silicone dioxide/Acrylate core-shell polymerization was carried out on the surface of silicone dioxide particle without forming the new silicone dioxide particle during acrylate shell polymerization in the inorganic/organic core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer and morphology of latex by scanning electron microscope(SEM).

• Transactions on Electrical and Electronic Materials
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• 제10권1호
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• pp.9-15
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• 2009

There is a growing demand for a high voltage silicone rubber composite with high mechanical property and high electrical property. The effect of modified cross-linking agent on the mechanical, electrical properties, and short-circuit test performance of silicone rubber insulators have been investigated. To use base polymer, the various silicone polymers were prepared by the equilibrium polymerization. Aluminum trihydrate surface was treated by vinyl silane. Liquid silicone rubber nanocomposite was prepared from the compounding of VPMPS, HPDMS, catalyst, and alumina trihydrate modified with 1,3,5-trivinyl-l,3,5-trimethylcyclotrisiloxane. The mechanical property and electrical property for insulation materials were measured, indicating the high tensile strength and the good short-circuit property.

• Steel and Composite Structures
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• 제44권5호
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• pp.741-752
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• 2022

Earlier works have shown that excessive shear stiffness at the steel-concrete interface causes a non-uniform distribution of shear force in composite structures. When the shear studs are wrapped at the fixed end with flexible materials with a low elastic modulus, the shear stiffness at the interface is reduced. The objective of this study was to investigate the effect of silicone rubber-sleeve mounted on shear studs on the shear stiffness of steel-concrete composite structures. Eighteen push-out tests were conducted to investigate the mechanical behavior of silicone rubber-sleeved shear stud groups (SRS-SSG). The dimension and arrangement of silicon rubber-sleeves (SRS) were taken into consideration. Test results showed that the shear strength of SRS-SSG was higher than that of a shear stud group (SSG), without SRS. For SRS-SSG with SRS heights of 50 mm, 100 mm, 150 mm, the shear strengths were improved by 13%, 20% and 9%, respectively, compared to the SSG alone. The shear strengths of SRS-SSG with the SRS thickness of 2 mm and 4 mm were almost the same. The shear stiffness of the SRS-SSG specimens with SRS heights of 50 mm, 100 mm and 150 mm were 77%, 67% and 66% of the SSG specimens, respectively. Test results of specimens SSG-1 and predicted values based on the three design specifications were compared. The nominal single stud shear strength of SSG-1 specimens was closest to that calculated by the Chinese Code for Design of Steel Structures (GB50017-2017). An equation is proposed to consider the effects of SRS for GB50017-2017, and the predicted values based on the proposed equation agree well with the tested results of SRS-SSG.

• 한국응용과학기술학회지
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• 제27권1호
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• pp.93-97
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• 2010

Silicone dioxide absorbed polyoxyethylene alkylether sulfate (EU-S75D) surfactant was prepared. The core-shell composite of inorganic/organic were polymerized by using styrene(St) as a shell monomer and potassium persulfate(KPS) as an initiator. We studied the effect of surfactants on the core-shell structure of silicone dioxide/styrene in the presence of an anionic surfactant lauryl sulfate(SLS). The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer(TGA) and morphology of latex by scanning electron microscope(SEM).