분말 및 섬유 내화 필러로 충전된 실리콘 고무의 특성 비교

류현준(Hyun Jun Ryu),황소산(Sosan Hwang),김영선(Yeongseon Kim),진성훈(Sung-Hoon Jin),백성현(Sung-Hyeon Baeck),심상은(Sang Eun Shim) 한국고분자학회 2017 폴리머 Vol.41 No.6

최근 건축물의 대형 화재사고로 인해 불연, 난연, 내화 등의 소재 개발에 대한 관심이 커지고 있다. 특히, 자체적으로 불연 및 난연 성능을 나타내는 필러와 열적 특성이 우수한 실리콘 고무를 혼합한 복합 내화재료의 가능성은 크다. 본 연구에서는 내화 필러로서 사용되고 있는 분말 형태의 알루미나(AM), 운모(MC)와 섬유형의 미네랄 섬유, 유리섬유 총 4종류의 실리콘 복합체를 제작해 열적, 가교거동, 물리적 특성을 비교 분석하였다. 가스토치 화염시험, TGA 분석을 통해 미네랄 섬유와 유리 섬유 2종을 혼합한 실리콘 복합체의 내화 성능이 분말 형태의 필러를 혼합한 2종의 실리콘 복합체보다 우수함을 확인하였다. 또한 TGA 분석 시 Horowitz-Metzger 방법을 이용하여 4종 필러 실리콘 복합체의 승온속도에 따른 열분해 활성화 에너지를 계산하였다. 만능재료시험기(UTM)를 통해 분말 형태의 필러 2종을 혼합한 실리콘고무 복합체는 인장, 인열, 신장률에서 우수한 특성을 나타내었고, 섬유 형태의 필러 2종을 혼합한 실리콘고무 복합체는 압축강도, 경도에서 우수한 특성을 보여 주었다. Recently, there has been a growing interest in the development of non-flammable, flame-retardant, and fireproofing materials due to large-scale fires in buildings. Especially, there is a great possibility of researching non-flammable or flame-retardant fillers/silicone rubber composites having excellent thermal properties. In this study, four types of silicone rubber composites were analyzed for thermal, curing, and physical properties. It was confirmed that the fireproofing performance of mineral fiber and glass fiber/silicone composites was superior to those of two powder type filler composites examined by gas-torch flame test and thermogravimetric analysis (TGA). Also, thermal decomposition activation energies were calculated by the Horowitz-Metzger method by TGA. Particulate fillers/silicone rubber composites show greater tensile, tear, and elongation properties and fibrous fillers/silicone rubber composites have improved properties in terms of compressive strength and hardness examined by universal material testing machine (UTM).

무기계 내화 필러로 충전된 실리콘 고무 복합체의 열적, 물리적 특성

류현준(Hyun Jun Ryu),조선태(Sun Tae Cho),김영선(Young Seon Kim),백성현(Sung-Hyeon Baeck),진성훈(Sung Hoon Jin),심상은(Sang Eun Shim) 한국고분자학회 2017 폴리머 Vol.41 No.3

무기계 내화 필러는 실리콘 고무의 내화 성능 보강재로서 많은 관심을 받고 있다. 본 연구에서는 실리콘 고무 내화 필러로서 잘 알려진 수산화마그네슘(MDH), 수산화알루미늄(ATH)과 미네랄 울 2종의 실리콘 복합체를 제작해 열적, 물리적 특성을 비교 분석하였다. 가스토치 화염시험, 콘칼로리미터, TGA 분석을 통해 미네랄 울 2종의 내화 성능이 기존의 내화 필러 복합체보다 우수함을 확인하였다. 주사전자현미경(SEM), 만능재료시험기(UTM)를 통해 필러의 표면적이 큰 MDH를 실리콘 고무에 효과적으로 분산시킨 MDH/실리콘 고무 복합체가 인장, 인열, 신장율에서 우수한 특성을 나타냈고, 미네랄 울/실리콘 고무 복합체는 (MDH, ATH)/실리콘 고무 복합체에 비해 압축강도, 경도에서 우수한 특성을 확인하였다. Inorganic fillers have attracted a great deal of interest as reinforcing materials for fire-proof performance in silicone rubber (SR). In this study, magnesium hydroxide (MDH) and aluminium hydroxide (ATH)/SR composites, well known fire-proof materials, and mineral wool/SR composites were analyzed for thermal and physical properties. It was confirmed that mineral wool/SR composites have an improved fire-proof performance than the (MDH, ATH)/SR composites through gas torch flame test, cone calorimeter, and thermogravimetric analysis (TGA). MDH/SR shows great tensile, tear strength and elongation at break through SEM and UTM due to the fine dispersion of MDH in SR. Also, mineral wool/SR composites show compressive strength and hardness properties higher than those of (MDH, ATH)/SR composites.

리튬/공기 이차전지의 충방전 특성과 사이클 특성에 미치는 탄소의 영향 고찰

최현아 ( Hyun A Choi ),고보경 ( Bo Kyung Ko ),심상은 ( Sang Eun Shim ),백성현 ( Sung Hyeon Baeck ) 대한금속재료학회(구 대한금속학회) 2014 대한금속·재료학회지 Vol.52 No.4

Three different carbon blacks (Vulcan, Ketjen Black, and 1:1 mixture of the two) are used as cathode catalysts for a lithium/air secondary battery, and their electrochemical properties are investigated. The surface morphology change after discharge is examined using scanning electron microscopy (SEM), and the discharge products are analyzed using Fourier transform-infrared spectroscopy (FT-IR). In order to measure the electrochemical properties, the charge and discharge measurements are conducted at a constant current density of 0.2 mA/cm2, which monitors the voltage change. Electrochemical impedance spectroscopy (EIS) analyses are also performed in order to examine the change in the charge transfer resistance during the charge-discharge process. Compared with both the Ketjen black and Vulcan, the 1:1 mixture of the two carbon blacks exhibits the best performance as a cathode for the Li/air secondary battery, which results from a synergistic effect that exploits-both carbon blacks.

무기계 내화 필러 및 팽창재료로 충전된 실리콘 고무 복합체의 열적 안정성과 기계적 특성

황소산(Sosan Hwang),류현준(Hyun Jun Ryu),김영선(Youngseon Kim),소재일(Jae Il So),진성훈(Sung Hoon Jin),백성현(Sung-Hyeon Baeck),심상은(Sang Eun Shim) 한국고분자학회 2018 폴리머 Vol.42 No.3

본 연구에는 무기계 내화 필러와 팽창재료를 충전한 실리콘 고무 복합체의 내화 성능과 열적 안정성 및 기계적 강도를 분석하였다. 가스 토치 화염시험과 열 중량분석(TGA)을 통해 미네랄 섬유(mineral fiber)/실리콘 고무 복합체는 규회석(wollastonite)/실리콘 고무 복합체와 운모(mica)/실리콘 고무 복합체보다 내화 성능이 우수하다는 것을 확인하였다. 주사전자현미경(SEM)을 통해 규회석은 실리콘 고무에 분산성이 양호함을 확인하였고, 만능재료분석기(UTM)를 통해 분석한 결과 기계적 강도가 가장 우수했다. 팽창재료(팽창흑연 및 팽창질석) 2종은 가스 토치 화염시험 결과 내화 필러/실리콘 고무 복합체의 내화성능을 보다 향상시킬 수 있다는 것을 확인하였다. 특히, 팽창흑연이 충전된 실리콘 고무 복합체가 팽창질석이 충전된 실리콘 고무 복합체보다 내화성능이 더 우수함을 확인하였다. 하지만, 기계적 특성의 경우, 팽창질석이 충전된 실리콘 고무 복합체가 팽창흑연이 충전된 실리콘 고무 복합체보다 다소 우수하였다. In this study, mechanical properties and thermal stability of silicone rubber (SR) composites filled with various inorganic fire-proof fillers and expandable materials were evaluated. A fire resistance tested by gas torch flame tests and thermogravimetric analysis (TGA) of Mineral fiber/SR (F/SR) composites were superior to wollastonite/SR (W/SR) and Mica/SR (M/SR) composites. W was well dispersed in SR observed by scanning electron microscope (SEM) and the mechanical strength of W/SR composites was greatest analyzed by universal material analyzer (UTM). Expandable graphite (EG)/SR composites had improved a fire resistance than that of expanded vermiculite (EV)/SR composites. Especially, the fire resistance of EG/SR composite was superior to the EV/SR composite. However, the mechanical properties of EV/SR composites were only slightly higher than those of EG/SR composites.

전사법으로 제조한 SOFC용 YSZ 전해질 전사지의 치밀화 및 전기화학적 특성

조해란 ( Hae Ran Cho ),최병현 ( Byung Hyun Choi ),안용태 ( Yong Tae An ),백성현 ( Sung Hyeon Baeck ),노광철 ( Kwang Chul Roh ),박선민 ( Sun Min Park ) 대한금속재료학회(구 대한금속학회) 2012 대한금속·재료학회지 Vol.50 No.9

Decalcomania is a new method for SOFCs (solid oxide fuel cells) unit cell fabrication. A tight and dense 5 ㎛Yttria-stabilized zirconia (8YSZ) electrolyte layer on anode substrate was fabricated by the decalcomania method. After 8YSZ as the electrolyte starting material was calcined at 1200℃, the particle size was controlled by the attrition mill. The median particle size (D50) of each 8YSZ was 39.6 ㎛, 9.30 ㎛, 6.35 ㎛, and 3.16 ㎛, respectively. The anode substrate was coated with decalcomania papers which were made by using 8YSZ with different median particle sizes. In order to investigate the effect of median particle sizes and sintering conditions on the electrolyte density, each sample was sintered for 2, 5 and 10 h, respectively. 8YSZ with a median particle size of 3.16 ㎛which was sintered at 1400℃ for 10 had the highest density. With this 8YSZ, a SOFCs unit cell was manufactured with a 5 ㎛layer by the decalcomania method. Then the unit cell was run at 800℃. The Open Circuit Voltage (OCV) and Maximum power density (MPD) was 1.12 V and 650 mW/cm2, respectively.

전사법에 의한 SOFC 연료극 지지체 단위셀 구성에서 기능층의 효과

조해란 ( Hae Ran Ch ),최병현 ( Byung Hyun Choi ),안용태 ( Yong Tae An ),구자빈 ( Ja Bin Koo ),백성현 ( Sung Hyeon Baeck ),노광철 ( Kwang Chul Roh ),지미정 ( Mi Jung Ji ),박선민 ( Sun Min Park ) 대한금속재료학회(구 대한금속학회) 2013 대한금속·재료학회지 Vol.51 No.2

In this study, we fabricated anode-supported solid oxide fuel cells by the decalcomania method. To investigate the effect of the anode functional layer (AFL) in a cell, AFL decalcomania paper was coated between the electrolyte and the anode support. The results showed that the surface roughness of the electrolyte coated on the anode support was not uniform (Ra = 7.86 nm), but that of electrolyte coated on AFL was uniform. A thin electrolyte layer with very low surface roughness was obtained. Then Ra was 2.65 nm. In this case, while the output power of the cell with the AFL (Cell 2) had an open circuit voltage (OCV) of 1.12 V and a maximum power density (MPD) of 650 mW cm-2 at 800℃, the cell without the AFL layer (Cell 1) had an OCV of 0.9 V and an MPD of 635 mW cm-

Effects of Silane Coupling Agent on the Mechanical and Thermal Properties of Silica/Polypropylene Composites

Minchul Lee(이민철),Yeongseon Kim(김영선),Hyunjun Ryu(류현준),Sung-Hyun Baeck(백성현),Sang Eun Shim(심상은) 한국고분자학회 2017 폴리머 Vol.41 No.4

실란 커플링제 도입에 따라 silica가 충전된 폴리프로필렌의 기계적, 열적 물성에 미치는 영향을 살펴보았다. Epoxy, amino와 methacryloxy 작용기를 가지고 있는 실란 커플링제를 사용하였다. 종류, 농도와 실란 커플링제의 처리방법에 따라 silica/PP 복합체의 인장강도, 굴곡강도, 충격강도 및 열적안정성을 분석하였다. 용융혼합 및 압축성형에 의해 제조된 복합재료 샘플의 기계적 특성을 조사하기 위해 만능재료시험기와 충격시험기를 사용하였고, 열적특성을 조사하기 위해, TGA와 DSC를 사용하였다. 건식방법으로 amino 작용기를 가지고 있는 실란 커플링제를 5 wt% 혼합한 silica/PP 복합체가 기계적 물성과 열적 물성이 가장 우수한 것으로 확인되었다. The effect of silane coupling agent on the mechanical and thermal properties of silica/polypropylene composite was studied. Epoxy, amino, and methacryloxy silanes were introduced as coupling agents. Silica/PP composites were investigated in terms of flexural, tensile, impact strength, and thermal stability in accordance with type, concentration, and processing methods of silane coupling agent. Mechanical properties of the composites prepared by melt-mixing and compression molding were tested by UTM and impact tester, and thermal properties were analyzed by TGA and DSC. As a result, it was confirmed that the silica/PP composite mixed with 5 wt% amino-functionalized silane prepared by dry method showed the highest mechanical and thermal properties.